What do I think people do when they retire?

When people retire I think that they start to take lots of vacations. Some of them may go get a part time job just to have some extra money. That what my grandparents did to fill there free time. Some of them may take up a new hobby. I have seen a lot of retired people who do nothing with there lives and I don't get why. They should have fun stuff to do. they worked there whole life. That is what I think retired people do.