But special relativity? Yes, Henri Poincare had already come up with a mathematically equivalent theory to special relativity. Einstein's is a much simpler theory by all means, but the original commenter talking about it like it came out of no where and people must have thought Einstein was crazy or lost his mind, that's just a gross misunderstanding of history.

If anything, Einstein's theory of special relativity gained acceptance rather quickly because it basically converged to where physics was already heading.