By Rich Copley, Lexington Herald-Leader (TNS)

The summer of 1980 was the first time I can remember feeling like I had made a pop culture discovery. There was this guy named David Letterman, and he had this weird little comedy show on NBC in the morning.

It was there that I saw for the first time bits like Stupid Pet Tricks and met characters like Biff Henderson. It never felt quite right at that hour, which is probably why Letterman’s daytime show barely lasted longer than the summer.

But as we all know, David Letterman lasted a lot longer.

I vaguely remember hearing in early 1982 that a new show was coming on after The Tonight Show Starring Johnny Carson, with David Letterman as the host. As a kid with night owl and procrastination tendencies, I saw a fair amount of the early ’80s Late Night with David Letterman broadcasts in the summer or when I put off doing homework too long.

It was great. Early, early in the morning, Letterman seemed to be left to his own devices, to do crazy things like dropping items off buildings to see what happened or dress up in a Velcro suit and jump up against a Velcro wall. He booked offbeat guests like Andy Kaufman and set the tradition of late, late shows giving budding bands like R.E.M. their network TV debuts.

That was decades ago, but I still feel too young to see a guy I watched start his career retire as a TV and pop culture institution. That’s what’s going to happen May 20, when Letterman bids farewell to late night with the final episode of CBS’ The Late Show with David Letterman.

Letterman never got the Tonight Show host’s chair he so wanted, following the departure of his hero, Carson. But his farewell will be second only to Carson’s signoff in 1992 in terms of impact. That’s in part because while Carson mastered the late-night chatter show form, Letterman shook it up.

On The Late Show, it became about so much more than a monologue, a desk and microphone and guests. Letterman brought a late 20th century sensibility (and overt cynicism) to the form and advanced the idea of the host as a maestro of mayhem. Certainly Jimmy Fallon is adding a new century spin to his work as Late Night and now Tonight Show host, and he’s the most accomplished entertainer to hold one of these chairs. But he plays a hand Letterman played a big part in dealing.

But the main reason this is such a huge farewell is we like Letterman. Yeah, he’s a curmudgeon, and he’s far from perfect. But he’s the kind of curmudgeon you always knew meant well and were happy to find in your living room.

After the terror attacks of Sept. 11, 2001, it is still Letterman’s plainspoken response I remember best. We weathered scandal and health scare with Letterman, and it seemed so natural because he never tried to be anything more than a guy from Indiana.

It helps explain why NBC has had to deal for decades with the perception that it cheated Letterman out of the Tonight Show job when it went to Jay Leno. So Letterman started a new tradition on CBS that Stephen Colbert will continue in the fall.

Letterman retires leaving a legacy of two late-night institutions, a whole lot of fun, and maybe some English essays that weren’t everything they could have been.

(c)2015 Lexington Herald-Leader (Lexington, Ky.), Distributed by Tribune Content Agency, LLC.