I get that a lot playing Dominion - my g/f wins way more than the odds suggest and at the end of most games comments that I got way too carried away with trying to build a cool engine and forgot the point of the game...unfortunately she's usually right.
I am totally my worst enemy. I get wrapped up in the "cool" thing. Then, three turns later I realize, "Dang I shouldn't have done that, but it was cool at the time."