I was 66 or 67 and was called into a small room with the CEO, the personnel person, and my boss. I knew what was going to happen before a single word was spoken. I didn't "take the leap", they tossed me out.
OK, to be fair, I knew it was coming and they were as nice as they could be about it. And I got a nice severance payment. So I really can't complain.
My first thoughts were how I was going to pay all the bills. I wasn't at all sure I was financially ready for it. The company had no pension plan so my own savings and SS were what I had to work with. But, it has been about 13 or 14 years now and everything worked out. Still in the same house and haven't missed a single mortgage or tax payment. No credit card dept other than this month's bills. All in all, I am doing OK. So, do I wish I had done it sooner. Well, I don't know. I could answer both ways. I liked working too.
As for keeping busy, that is the only way. I now have time for my personal projects and can't keep up with them. I occasionally earn some extra money by writing about my projects and getting it published. That's nice, but I don't really need it. So, retirement has been OK. And if I can do it, anybody can. Well, almost anybody.