David Letterman is feeling the woes that many parents do.

Letterman’s only son, 18-year-old Harry Joseph Letterman, made the voyage to college on Tuesday. Letterman, 75, took the transition harder than he expected.

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“The separation of the kid leaving home, I thought it would be nothing but it’s devastating,” Letterman told “Jimmy Kimmel Live!” on Tuesday, per DailyMail. “Am I the only one that feels that way?

“He’s been gone a month today. We had a truckload of crap to take up to his room; and his room, man, it’s not as big as the desk.”

Letterman detailed his amusing first conversation with his son after he settled into his new environment.

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“I said, ‘Harry, have you met the kid yet that sells weed?’ I’m thinking this would get a good laugh,” Letterman said. “Harry says, ‘I cannot confirm or deny.'”

Letterman shares Harry with Regina Lasko, Letterman’s wife since 2009.