Checkmate in 3 moves

 Nothing spectacular on my part of course, just a major goof by my opponent. Still, I doubt I'll ever checkmate anyone this quickly ever again.

This is what' called a "Fool's Mate"  (your opponent, not you).  

http://www.chess.com/chessopedia/view/fools-mate  

When I was very young I found out this by myself also, along with the Scholar's mate.  I only learned the names later.     

I've always known fools mate to be the 4 move checkmate using the bishop and queen (e4, Bc4, Qf3, Qxf7#) . Easily thwarted and positionally unsound.

I think trying to pull it off shows a lack of respect for your opponent. In this case I saw (2. f4) as a blunder since the pawn cannot be retaken, and thought taking was the correct accurate move. I figured he might see that and just deal with being a pawn down and having an iscolated g-pawn and an exposed king, in exchange for an open h-file for his rook. Not a fair trade IMO, but I'm not sure what else he could do.