"Oh that's right, I don't care!"
I mean, you can't blame the guy for trying, right? There are a lot of specifics and symbols and general rules of appropriation for Twitter.
Dave Letterman's two biggest competitors, Jimmy Fallon and Jimmy Kimmel, are extremely active on Twitter, so it's no wonder that his employees are encouraging him to get familiar with the social network. So smack dab in the middle of Monday's Top Ten list, he put forth some sort of an effort to tweet. But he clearly couldn't care less.
See his awkward but funny attempts below.