Problems with protons? We've got 'em. Like, have you ever tried to fit a proton into a Klein bottle?
Or what about protons in a quantum superposition? That's just a recipe for trouble, folks.
But don't just take our word for it, click here to learn about ProtonProblems2: More Protonic Predicaments.
Or, if you're feeling particularly masochistic, click here to read about ProtonProblems3: The Protonic Pileup.