What's the most basic thing you can't do?

My parents used to tell me as a kid that I couldn't whistle because I wasn't eating my pizza crust. After I started eating the crust I learned how to whistle.

Have you tried eating crust?

Me neither, and for the same reason.

I lost my ability to whistle in a tragic playground accident when my front teeth met the skull of a friend travelling in the other direction. Ever since, crooked front tooth.