That only works against a badly prepared player. Learning an opening isn't just about memorising moves, it is also about understanding why the moves -- both your own and your opponent's -- are good. If you have studied an opening well, you will understand why a stupid move is stupid and be able to punish it. Of course you may still end up messing things up and lose the game later on, but you should be able to emerge from the opening with an advantage.

Openings do not necessary break here. They are meant to take advantage of a situation by a series of branched off movement. If you are not making good enough guess about why a particular opening is played - making one move to pull somebody out of the book won't do much good.