I bought a campervan and toured Europe spending months away at a time with my wife. That, coupled with learning a language that I was able to put to good use on my travels, was therapeutic and helped keep my brain and body active. That coupled with other travel kept me busy for a while but walking is now my main pastime. However, I've noticed that if I relax for a few days with no exercise it is difficult to get going again. So my advice is to keep active but to posters who dread retirement........................ don't. You have to retire sometime and it is better to do it while you are fit enough to enjoy yourself.