Not a coworker, but at my college there's this 40+ year old dude that's trying to Get Back In the Industry and he's the most dual Condescending/Incompetent person in the entire Computer Science department. I appreciate his wanting to stay relevant, but he stops lectures every few minutes to try and explain something (usually inaccurately) before the professor does, and loudly critizes things that don't matter, and likes to try and give impromptu speeches in the library and talk to people when they're working. I've never met someone so mediocre and self-centered in my life.

Also, he spends a lot of time trying to talk with some of the younger women in the class and it's super Creepy. So there's the tea on that.