Speckle Monkey

An immature person, usually a grown adult, who tends to focus on the little things that make absolutely no difference and waste their life lost in trying to figure them out.

Sid: Hey man, what's going on?
Goob: I'm trying to figure this out!
Sid: Figure what out?
Goob: Where the water keeps going.
Sid: Down the drain buddy.
Goob: Yeah but, then where?
Sid: Who cares you speckle monkey.