Dan had only been doing comedy for a few months in New York when he was asked to do a set at Gotham Comedy Club. There were rumors floating around that Jerry Seinfeld was going to show up to do a set, and sure enough, about midway through the show, Dan saw Jerry in the lobby, talking with a couple of people.
Dan huddled with the other no-name nobody comedians, and they were all quaking in their boots at the sight of comedy royalty across the lobby. Dan said that he would like to go up and talk to Seinfeld, but the other comedians bristled, saying that that would be the ultimate, horrifying faux pas. Dan has never been particularly good at following rules, or doing what other people tell him to do, so gathering all the chutzpah he could muster, he marched up to Seinfeld. It was truly an out-of-body experience. Dan heard himself say "Jerry..." (He didn't say Mr. Seinfeld, only because Dan hates when people call him Mr. Nainan) "... I'm just starting out in comedy, and I'm wondering if you might have any advice for me?"
The seconds ticked away, and Dan thought for certain that Seinfeld was going to open his mouth, scream at him, swallow him and eat him for dinner. Instead, Seinfeld said eight words to him that Dan would never forget, eight words that would change his life – "You should work clean - you will work everywhere!" Dan mumbled a thank you and scurried away, feeling like the Cowardly Lion running from the Wizard of Oz.
To the understandable delight and amazement of the crowd, Seinfeld was introduced, and he proceeded to perform his upcoming David Letterman set. When he had finished, he said that he had a little bit of extra time to take questions. Some cretin who was extremely drunk asked him a question that was completely unintelligible. After a pregnant silence, Seinfeld finally said "Well you gave it a shot", to uproarious laughter. Some lady said "Can you do that bit about your wedding?". Seinfeld said, "I don't really have time to do that bit - where did you see me do it? The lady replied, "I don't know… Gotham?" Whereupon Seinfeld said nothing but just pointed to the Gotham sign on the wall, which brought the house down.
Seinfeld's advice has proven to be quite fruitful for Dan. He could never do the shows he does if he used any profanity or vulgarity.