Letterman's 60! When did that happen?

Yesterday was David Letterman's 60th birthday and the weird thing is I felt old.
He's been on the air doing his thing for 25 years but for some reason it's his age that's struck me as a gauge of my advancing chronology.
See if he's 60 then I must be getting old too.
Weird huh.

I started watching him a bit on his failed daytime show but I really got into him when he went Late Night in 82. I was hooked.
I loved Carson but this guy was new, fresh and very self-referential.
I was 22 and hosting a kids TV show on CBC Alberta at the time and I ripped him off big-time.
Not so much specific bits but his mannerisms and style. I thought he was the coolest TV dude and I dug whole shows vibe. Larry Bud, The Velcro Wall, Dropping Stuff off Buildings, Paul Shafer and Chris Elliot-the guy who lives under the stairs.

Now he's 60 and I'm 47. I've long given up pretending I was him but I haven't stopped liking his style. I don't watch regularly anymore but when I do I always get a laugh.
David-Freaking-Letterman is 60.
How Freaking -Old Do I Feel?
Here's a classic Letterman interview with Crispin Glover. Years after this I interviewed Crispin and he couldn't have been nicer. Never once tried to kick me in the head.