What does quantum mechanics tell us about reality?
That's the question that got me started in physics.
Now, after 10 years of study, a PhD and three postdocs, I can finally say that I have no idea.
"The most perfect philosophy of the natural kind only staves off our ignorance a little longer ... the observation of human blindness and weakness is the result of all philosophy, and meets us at every turn"
-- David Hume