the past has no existence except as it is recorded in the present. (...) we would seem forced to say that no phenomenon is a phenomenon until it is a… - Kenneth W. Ford

Never make a calculation until you know the answer. Make an estimate before every calculation, try a simple physical argument (symmetry! invariance! conservation!) before every derivation, guess the answer to every paradox and puzzle. Courage: No one else needs to know what the guess is. Therefore make it quickly, by instinct. A right guess reinforces this instinct. A wrong guess brings the refreshment of surprise. In either case life as a spacetime expert, however long, is more fun!

Physicists love this number not just because it is dimensionless, but also because it is a combination of three fundamental constants of nature. Why do these constants come together to make the particular number 1/137.036 and not some other number?

Spacetime grips mass, telling it how to move...
Mass grips spacetime, telling it how to curve