travelling without an id wastes your time, too, when they cart you off. Travel with an id, but feign ignorance, and start pulling out all your old high-school library cards, book-club cards, AAA membership, etc., etc. When they start bringing out the handcuffs, "discover" your ID, "Oh, what about this one? Is that what you want?"

Or, bring a permission slip from your mother. Those should work great.