In the late 1970s, Knocked Up director Judd Apatow, then about 12 years old, went to visit his grandmother in California. As he’d done during previous trips out west, Apatow asked if they could drive past Steve Martin’s house on the way to his grandma’s, not expecting that he would actually get to see Martin in the process. However, Martin happened to be standing in his front yard as they pulled up, and Apatow decided to hop out of the car and ask the comedian for his autograph. Unbeknownst to Apatow, Martin had a strict policy at the time about not signing autographs at his house.

“Will you sign it in the street?” Apatow fired back. Martin then politely explained to the future filmmaker that signing an autograph for him would just lead to a flood of fans coming to his home, asking him to do the same for them. Defeated and confused, Apatow returned to the car, trying to wrap his head around Martin’s logic. Instead of walking away empty-handed, the young Apatow hatched a plan to get what he wanted out of his idol: He’d write him a threatening letter that would force him to see the error of his ways.

Judd Apatow Once Threatened Steve Martin Into Giving Him an Autograph

Apatow started off by telling Martin that he was his biggest admirer, but that he felt the comic treated his fans poorly. After all, Apatow pointed out, if it hadn’t been for people like him buying Martin’s books and albums and going to see his movies, he wouldn’t be living in that house in the first place. Finally, the pre-teen hit his hero with a hilarious ultimatum: If Martin didn’t respond to him with a signed apology, he would send the actor’s address to Homes of the Stars. Once that happened, Apatow warned, tour buses would pass by his house 24/7.

To Apatow’s surprise, a few months down the road, he received a signed copy of Martin’s 1977 book Cruel Shoes. Inside, Martin wrote the following: “Sorry Judd—I didn’t realize you were The Judd Apatow!” Apatow later said the experience had a great impact on him because it made him realize that if he could make someone as funny as Martin laugh, maybe he had what it took to do comedy.

The pair eventually got together for a Vanity Fair profile in 2012, where they shared the story of their first encounter, and Martin marveled at how prophetic his words turned out to be.