Have you ever pushed a door that says "pull" and then felt like the dumbest guy in all the land? Me too, buddy. Sorry I can't always intuit what it's going to be, and I don't always have the wherewithal to look and see if there's a sign. It's one of those stupid human moments that'll humble you in an instant. We can walk around having complex thoughts and ideas and dreams but push a pull door and wait a few moments too long to realize it. I bet Einstein did it at least once. We're all just tall monkeys at the end of the day.
But it goes to show you just how important signs are in our day-to-day life. We need them to avoid ridiculous blunders. So the people in charge of them better know what they're doing, unlike the folks behind these hilarious design fails.