This kills me. I just said, "Hey man, what's going on?" to my co-worker and he goes, "Good, you?"

Ok, either you are too caught up in your own moment to listen to me (which makes you a dick) or you simply have no idea how to differentiate "what" and "how" (which makes you an idiot).

It's ok if you correct yourself and we laugh it off, and it's even ok if you know you fucked up but are embarrassed about it so you ignore it to quickly get it behind you, but this guy does not know the difference. That's what kills me. To me it's no different than:

*"So, what did you do last night?"

-"Fine, thanks."

*"......."