It is a relief to be able to kick back and not HAVE to do anything. I really enjoyed not having to work, like you I started at 12-13. First year was great, then I started looking for more to do, helped a friend build an airplane, then "sort-of" started looking for a part time job. Finally gave up and just started a new job last week. I'll probably do that for 1-3 years to buy an RV or airplane, then cut back to part time.
The important difference is that I'll be working because I want to, not because I have to. Different people react differently to retirement. It's a bigger change than I thought it would be.
I heard the call to do nothing. So I answered it.