Sad thing is, a lot of companies make you go cold turkey, instead of cutting your hours for a while to help wean off. One of my coworkers just retired after 41 years. They handed him his proverbial watch and waved good bye. I figured I would give him a few weeks to settle in before I give him a call for lunch, see how things are going, but I don't see him sitting still. But another good friend and coworker retired to sitting around the house, like my grandfather, and his life is slowly going to pot.
Personally, I think we (as americans) need to diversify our daily lives a bit. High schoolers need to spend less time with their butts in a seat and more time doing some real work, it would help them appreciate their education. Workers need to spend more time in the classroom, traveling, and with their families, becoming smarter, exposed, and more motivated workers and "retirees" need to keep working in the capacity that they are able but retain the flexibility to do what they want, when they want, which is why most of us want to retire anyway.
I was fortunate enough to be able to work and educate myself at the same time with a MWF/TT schedule. I loved it, I never had to do the same thing two days in a row!