Quantum mechanics as it stands would be perfect if we didn't have the quantum-gravity issue and a few other very deep fundamental problems.
Does Some Deeper Level of Physics Underlie Quantum Mechanics? An Interview with Nobelist Gerard 't Hooft
If you really want to contribute to our theoretical understanding of physical laws - and it is an exciting experience if you succeed! - there are many things you need to know. First of all, be serious about it!Gerardus 't Hooft
On your way towards becoming a bad theoretician, take your own immature theory, stop checking it for mistakes, don't listen to colleagues who do spot weaknesses, and start admiring your own infallible intelligence.Gerardus 't Hooft