The door opening onto the wrong floor gives certainty a quick practical correction.

Certainty gets corrected most efficiently by the world rather than by argument. You were sure it was the fourth floor, the doors open, and the corridor is obviously not yours: no debate, no embarrassment worth the name, just a fact arriving in under a second. Most confident errors would be cheap if they were tested this quickly.

Look for ways to check a belief that cost almost nothing: ask the question, open the door, run the small version first. Treat the correction as information rather than as a small humiliation. The alternative is being sure for much longer and finding out at greater expense.