There may be fairies at the bottom of the garden. There is no evidence for it, but you can't prove that there aren't any, so shouldn't we be agnostic with respect to fairies?
“I'm no hero. Heroes don't come back. Survivors return home. Heroes never come home. If anyone thinks I'm a hero, I'm not.”
“Science, like art, religion, commerce, warfare, and even sleep, is based on presuppositions.”