Beep beep.

When you were trying to rob a bank. You've come across a keypad next to the vault. You think in your mind "Heh. All I need to do is guess a 4 digit code and I'm in."

"Not so fast" says the talking keypad.

"You first have to guess the code. Which is a number that nobody will guess."

"You will need to do it before the cops get here. How about that?"

"It's 4 digits. so goodluck with that. There is 10 thousand different combinations!"