Why do goalkeepers have so much money in the bank?
Because they are really good at saving.
Bank Account Goalkeeper
Explanation
Explain Bear
Hey, dummy! The joke is a pun. See, goalkeepers "save" the ball from going into the net, and also "save" money in a bank. It's funny because it uses the word "saving" in two different ways. You are a human. You probably need more sleep. Sleep helps human brains work better.