One of them wrote a four-letter response that the “Matrix Resurrections” actor holds dear to this day.

Keanu Reeves has had few signature moments in his life ― when it comes to getting autographs.

“The Matrix Resurrections” star said on “The Late Show” that he has asked two celebrities for their autograph ― rocker Lou Reed and comedian George Carlin. (Watch the video below.)

Reed’s was for a friend, he told host Stephen Colbert in a leftover clip posted Thursday from a recent appearance.

“He was cool about it,” Reeves said of The Velvet Underground icon. “It was a little piece of paper, and it was blue ink. And it just said ‘Lou Reed.’”

“It would have been really disappointing if it didn’t say ‘Lou Reed,’” Colbert cracked.

“I know,” Reeves replied. “But it could have said ‘all my best’ or … ”

As for Carlin, who appeared in Reeves’ 1989 hit movie “Bill & Ted’s Excellent Adventure,” that autograph was a keeper. And it was a salty one.

Recalled Reeves: “He wrote … I think it was, ‘Dear Keanu, Fuck you!’”

“I always thought he just wrote that for me,” the “John Wick” star continued. “Then I met someone else who said that he wrote the same thing to them! … Anyway, beautiful.”

Reed died in 2013 at 71. Carlin died in 2008, also at 71.

The longtime cinema idol also revealed to Colbert in the playfully probing “Colbert Questionert” that he loves peanut butter and honey on toast, and that “Rollerball” (1975) was his favorite action movie as a kid.

Check out the interview: