From the NYT Magazine:
The more we talked over the following 18 months, however, the more painful his adolescence began to sound. Apatow was always small for his age, and he grew adept at making fun of himself before others could. He began audiotaping “Saturday Night Live” when he was 11, transcribing the show and then trying to figure how they made it funny. When TV Guide arrived each week, Apatow would underline all the comics scheduled to appear on “The Mike Douglas Show.”
Apatow’s childhood hero was Steve Martin. On a summer trip to L.A., Apatow persuaded his grandparents to drive by Martin’s home until Apatow spied his hero in the driveway. Martin wouldn’t give him an autograph, so Apatow wrote him an angry letter saying it was his patronage of Martin’s projects that allowed him to live the high life. A few weeks later, Martin sent Apatow a copy of his book “Cruel Shoes” with an apology: “I’m sorry. I didn’t realize I was speaking to the Judd Apatow.”
Here.