Now, embarrassingly, I have forgotten why we play chicken with the universe in the first place. Can someone remind me what goes wrong if we don't?

cousin_it has a post about this here. (Mentioning me =])

(The important thing to note is that if you can prove both (A() = 1 => U() = 5) and (A() = 1 => U() = 10), then it follows that (A() != 1), and therefore this is impossible if we play chicken and our proof system is sound.)