Nearly all benefit, for me. I had a job I liked, and intended to work until at least 66 (full Soc Sec age for me), but I was offered a buyout in late 2007. The newspaper business and the economy were going down in tandem then, and I figured things weren't going to get better, so I reluctantly took the deal. Good thing: About half who got the offer turned it down, and they were laid off with a much less generous package six months later.
I'd intended to ride my bike six hours a day for a year, then make a slow cross-country trip, something I'd thought of for years. Unfortunately some health problems intervened (non-self inflicted, just one of those weird things), and I haven't been able to do that. But I'm doing a local radio talk show, writing for a couple of magazines (I was a newspaper reporter in real life) and have time to do the gardening and other hobbies I'd dabbled in before. Money's a little tight, mostly due to one big year the IRS can't ignore, but I wouldn't go back.
If there's a moral to the story, it's this: Have plans and a backup, because the plans might fall through. I fully expected to be spending my summers and falls on long bike tours, and still may be able to. For now, though, 20 miles is a long, painful ride. If I hadn't found other interests, I'd be eying the gun cabinet.