E=mc^2 is just one line, why did it take centuries to get to that?

I once got a bonus and gratz at an all hands for removing a single semicolon after a 2 week investigation.

I think that's the key. When something takes 2 weeks an outsider believes that it was complicated in ways they don't understand. When it takes 2 days they think it couldn't have been complex and wonder why it took so long.

There wasn’t an error in Safari, WebKit or something like that last decade that accepted invalid certificates because an extra semicolon? Either adding or removing it was not trivial tasks.