"Has anyone gathered all the pieces (of life's puzzle)?"
"Then don't make a picture."
As humans, we're incredibly intelligent creatures with problem solving skills, impressive memories, and vast imaginations. While this makes us think we're really starting to figure out life and how the Universe works, we really don't know much at all. Everything we know, we only know to a certain extent and the rest of it remains a mystery.
"I know that I know nothing" is a phrase often attributed to Plato talking about Socrates. I once had someone who was Catholic, and seemed bothered by my lack of religion, ask, "So, what DO you believe in?" I didn't have much of an answer for her, but now I know why. It's because I believe I don't know really know anything, and I think that's okay. I know I most likely will die without understanding life and existence, and I've accepted that. But that doesn't mean I won't wonder and investigate!