Beating my friend Steve that one time...
He was bragging about the Phyrexian Dreadnought he bought for $8 somewhere.. he said he put it in his four-color deck that has all the best creatures.. well, I know him, in his mind, "best" is a synonym of "biggest". I tell him I bet I can beat it, and he doesn't believe me.. I go get my red goblin/burn deck, he looks at a couple cards, he's laughing his ass off, because "all the cards suck!" and "it only has one color! you need LOTS of colors so you can get the best of each one!"
We sit down to play.. Before he even gets his first creature out, he's down by 10. I won.. but he still doesn't believe that fast decks can do anything. *sigh*