I actually remember when he had a daytime tv show. I was probably one of the few people who watched it but it was on in the summer while I was in high school.
Then he moved to really late night (11:30 where I lived). And the humor was perfect for a college student. Dan and I used to watch him every night. We still talk about things he did way back then.
The Suit of Velcro
Throwing things off the roof
Paul Newman on Letterman's first night in the Ed Sullivan Theater
Every Christmas taking the meatball off the top of tree with a football
Then there are the sayings. I wouldn't give his troubles to a monkey on a rock. All the squirrel/nut jokes. How he adored Johnny Carson.
We still joke about how Dave loves the kids. He did one bit where he asked a kid what his favorite food was and he said lettuce. Next shot had them eating heads of lettuce like they were apples. That still makes me chuckle.
Late night tv was forever changed by Dave. If you watch both Jimmy Fallon and Jimmy Kimmel and their tributes to Dave you know that their lives were changed by him.
Happy retirement Dave.