Someone that tends to point outthings that stand out like dogs balls. In other words, noticing the really obvious.
If you where to tell me GW was brainless, you'd be an Obviosaurus.
You know, that dumbass everyone gets to be when they've smoked too damn much. They can usually be detected by a: "Dude, I'm pretty high right now."
Commandment 3: Thou Shalt Not Be An Obviosaurus.