How mathematical proofs are obtained.

The above cartoon from Abstruse Goose demonstrates the not always linear path of new discoveries in mathematics. How mathematics is discovered is not the same as how mathematics is presented.

This also reminds me of a very famous humorous quote:

mathematicians can prove only trivial theorems, because every theorem that is proved is trivial!

Richard Feynman in “Surely You’re Joking, Mr. Feynman!”: Adventures of a Curious Character, Richard Feynman, Ralph Leighton (contributor), Edward Hutchings (editor), 1985, W W Norton, ISBN 0-393-01921-7