I live when you wonder and die when you know, I grow in the maybe and shrink in the so. I vanish when named, yet guide what you do. Half truth, half question, what am I to you?

You drop me in the toilet I float on water I'm cut and chopped Mathematicians deal with me , as do lumberjacks

I turn a knight dark Bring death to the ill Make a seeker wise An infuriating reply My presence or absence decides all

In a corner with friends, I am smaller than them. I am not right but that doesn’t mean I’m wrong. Neither obtuse or flexible.

I can be spoken, but never said. I can be written, but never read. I exist only when you don’t look for me. The moment you find me, I vanish. What am I?