Jack Benny became one of Dwayne's mentors during production of The Bob Cummings Show:

Jack spotted me and made his way through the crowd. We chatted for a moment about The Bob Cummings Show, then he took hold of my arm and told me that he had the most incredible experience that day and he just had to share it with me. I couldn't imagine what it could be but I figured it would be pretty good; after all, he was Jack Benny, a living legend.Jack squeezed my arm and proceeded to tell me that he had been out driving around and got hungry so he stopped at a restaurant called tiny Naylor's. He asked if I had ever been there. I had. Then, with great amazement and total sincerity, he told me that he had ordered a cheeseburger and that it was the best cheeseburger he had ever eaten. Then he asked me if I had ever had a glass of their water. A bit confused, I said I was sure I had. Jack squeezed my arm again and said, "Tiny Naylor's has the coldest and best-tasting water I've ever had." At that moment I realized there was no punch line, no great event; nothing had really happened to Jack besides eating a good cheeseburger and drinking a cold glass of water. Here was a man who was fabulously wealthy and one of the most famous entertainers in show business, and the simplest pleasure in life was a big deal to him. As I got to know Jack, I realised what all his friends knew, that he was not a comedian who told jokes like most comics; he was a serious and sincere and a wonderfully kind gentleman who just happened to be very funny.

"Uncle" Bob Cummings was eccentric, to say the least:

The next day Bob told me that were were going to visit a doctor friend of his on the East Side of the city before our luncheon interview. As we arrived at the doctor's office I realized that it was not a social visit, but that Bob was there for what he referred to as "a treatment". While waiting for the doctor Bob explained that whenever he was in New York he would come here because this doctor was famous for his youth serums. Bob told me that he received injections from the glands of a monkey and the sperm of a sheep. I just looked at him, waiting for the punch line, then I realized that he wasn't kidding. I knew that Bob was obsessed about staying young and maintaining a youthful appearance. His hair was dyed that strange henna red and he coloured his skin so that he always looked tan. During breaks in rehearsal he had a trainer who would not only massage Bob's arms, legs and back, he also specialized in massaging prostates. Bob swore that the prostate massage released some kind of endorphin that helped keep him full of energy. He offered me his trainer's services, but I felt that I had plenty of energy and I passed. I had thought I had heard everything when Bob told me about his massaged prostate, but that paled in comparison to getting injected with monkey glands and sheep sperm. When I pressed him about which glands of the monkey were used he gave a vague answer, then he was called into the examining room. As I waited for him all I could think about was some poor monkey losing his glands for some crazy youth serum. I had a pretty good idea which "glands" they were using. I also couldn't help thinking about the guy who had the job of retrieving the sperm of a sheep.

During his success as a teenager on The Bob Cummings Show, Dwayne was persuaded to record a single, School Dance. He then reluctantly went on tour, which included an unforgettable appearance on American Bandstand:

Standing backstage watching the other performers, I knew I was in over my head. Any ounce of self-confidence flew out the window as I watched the slick, hip, young heartthrobs talk and joke around. They didn't have a moment's concern about going on stage to sing and trying to stay on key.I was the second act on the show. The singer who went on before me was a South Philly homeboy named Frankie Avalon. Handsome and self-assured, Frankie wowed the crowd. Girls screamed and swooned as he danced around, singing his hit song, "De De Dinah". He was so relaxed and in charge I almost forgot that he was lip-syncing the record. I looked at him dressed in his bright red jacket, white pants, and white shoes, then I looked at myself in the backstage mirror in my gray herringbone sport coat, dark gray slacks, and black wing-tip shoes. Frankie looked like a rock-and-roll heartthrob; I looked like a fifty-year-old bank teller. How would I ever follow him? Frankie finished his song to deafening applause and screams, then he bounced off stage, flashed a perfect pearly white smile, and said, "I warmed them up for you, they're all yours". Sweat began to break out on my upper lip, and before I could think of some hip response, I could hear Dick Clark giving me a flowery introduction. Suddenly I was on stage.Looking out into the sea of screaming excited teens, I thought for a fleeting moment that maybe I had been too hard on myself, maybe I was just as much a teen singing sensation as this slick Avalon fellow. As the music started I tried to bounce around the stage and be loose like Frankie. I was only into the song a few bars when I could tell that I was already a few words behind. I could hear my recorded voice booming across the stage but my mouth was so out of synch that I looked like Charlie McCarthy. My lips kept flapping away but I just couldn't catch up. I also noticed that all the screaming had ceased and the once frenetic teens were just staring at me as I tried to desperately get back in sync, while continuing to bounce around to the beat. I thought the song would never end.

In Ski Party, Dwayne and Frankie Avalon met up again, but this time they were both dressed in drag:
	We were all decked out in our wigs and false eyelashes. As the [ski] lift slowly made its way up the mountain, imagine Frankie and me dressed in drag, hanging on to each other for dear life. Finally, we reached the top. Nearly frozen, we were helped out of the chair lift only to discover that it was too cold to film. The cameras were frozen, so we had to turn around and go back down the hill. We were both scared to death to get back on the lift, but it was either take the lift or ski down, and the latter was out of the question because neither of us could ski.
We felt like two fools as we finally hit the ground and were greeted by nearly twenty real skiers on the way up the mountain. I told Frankie that no one would recognize us dressed like women, so he made his way toward the lodge as I followed close behind. A tall, gorgeous blonde passed me and, as our eyes met, she stopped and said, "I know you, you're Dwayne Hickman. Look, everybody, it's Dobie Gillis".

Warren Beatty played Milton Armitage during the first season of Dobie Gillis:

On Warren's first day on the set we were getting ready to shoot a scene. As the director called for quiet, Warren held up his hand, moved me to one side, took his comb from his pocket and began combing his hair in his reflection in the camera lens. We all stood by and watched in amazement.

On another occasion, Tuesday, Warren, and I were rehearsing a scene in Charlie Wong's Ice Cream Parlor. Suddenly, Warren announced that he couldn't do the scene the way it was staged, and that it would have to be reblocked. When I asked him why, he gave me a disdainful look and condescendingly explained that the way he was seated had put his bad side to the camera. So we reblocked the scene, and this time Tuesday had a problem because now she was at a bad angle. So we reblocked again. By the time we finished I ended up with my back to the camera. When you did a scene with those two, it was every man for himself.

Sheila James, aka Dobie's "Zelda Gilroy", had an extraordinary memory:

As I got to know her better I realized that she was even brighter than the character Zelda. Gifted with a photographic memory, Sheila could learn a script after one reading. During rehearsal one day, Bob Denver, Sheila, and I were doing a scene. I gave Bob his cue and he replied with a totally inappropriate response. Sheila said, "Bob, you’ve jumped from page nine to page eleven. Your cue is at the top of page ten". We looked at her in amazement. Then Bob said that his script didn't have a page ten. When we asked him why, he replied, "Because my baby ate it". Sheila and I just looked at him and shook out heads. Of course, with Sheila around, who needed a script anyway.

And who could forget Maynard G. Krebs:

One of the first shows of the season was a spoof of Perry Mason. The episode, titled "Move Over, Perry Mason", had Maynard taking Dobie's dad to court after getting his hand caught in the grocery store's gumball machine. It was in this show that Maynard turns to Dobie and says, "Everybody tells me that I'm an accidental prune". And Dobie replies, "That's accident prone, Maynard". Maynard was always mixing his metaphors. "Dobie, I've been like a gallstone around your neck ..." -- Maynard, that's millstone!" or, "Dobie, do you think I look like a Ragged Muffin?" -- "Maynard, that's ragamuffin ... and the answer’s yes!"

Lee Marvin made quite an impression on Dwayne during the filming of Cat Ballou: During one scene in the outlaws' hideout called "Hole in the Wall", Lee and I were looking out of a window as Jane [Fonda] rode away on her horse. I couldn't help but notice Lee's eyes were darting all over the place as his tongue hung out and his head moved from side to side. After the scene I said, "Lee, what were you supposed to be doing?" Sarcastically, he said, "Who the hell knows? The audience will probably think I had gas!" I laughed, but he was the one who won an Oscar for Cat Ballou, not me.