The truly successful teacher is the one you will never need again.

Caution! Be very careful of false, meaningless, self-contradictory, and not even very funny warnings, like this one.

Not only don't I know what tomorrow will bring, I'm still not entirely certain what yesterday brought?

Without me there could be no everybody.

History records no more gallant struggle than that of humanity against the truth.

I have many unrecognized talents, but my faults have somehow succeeded in securing wide recognition.

Your reasoning is excellent, it's only your basic assumptions that are wrong.