If the inside of your helmet wasn't already head-shaped, you might want to consider something different next time.

You didn't mention how long your commute is, but if you're going to be cutting through parking lots, hopping curbs, and riding on poorly maintained roads, a tougher hybrid might save enough in repair costs to be well worth it. After all, every time you do something that would have damaged your all-carbon-fiber dreambike, you can toss half the would-have-been repair cost in a jar, and watch the dreambike fund grow while you still save money.