Used as an addendum by pompous, self important twats to validate their own (usually cretinous) arguments against others on the internet.

Also indicative of someone not used to normal conversation with real people.
Given how dumb your comments are I'm guessing you only ever follow football once every 4 years when the World Cup's on?
Thought so!
by Trumpton June 17, 2010
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Used after you shut someone up, for added emphasis.
Dude: Hey

Guy: But do you just wanna not though.

(Dude is left speechless)

Guy: Thought so.
by but dude...your face. March 18, 2006
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Said randomly to make the speaker appear smarter than they are, and to insult the person they're responding to.
"Dude, I'm tired."
"Uh, yeah. I thought so."
by Lomo March 1, 2004
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