Every theory presented as a scientific concept is just that; it's a theory that tries to explain more about the world than previous theories have done. It is open to being challenged and to being proven incorrect. ↗
Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? ↗
Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out. ↗
Some men have a silly theory about beautiful women - that somewhere along the line they'll turn into a monster. That movie gave them a chance to watch it happen. ↗
A mathematical theory is not to be considered complete until you have made it so clear that you can explain it to the first man whom you meet on the street. ↗
Psychotherapy theory turns it all on you: you are the one who is wrong. If a kid is having trouble or is discouraged, the problem is not just inside the kid; it's also in the system, the society. ↗