Suspense joke

There is a penguin whose home is very far from the polar bear's home. It takes 20 years to walk there. One day, the penguin was bored at home and prepared to go out with the polar bear. But on the way, he found that he had forgotten to lock the door. It's been 10 years, and the door is still locked. So the penguin went home and locked the door. After locking the door, the penguin set out again to look for the polar bear. He spent 40 years looking for polar bears.