I retired twice.. Once at 55 from the entertainment world..Then at 62 from the world of International Charity...I was retired for one year and that was that. I've been working ever since.
Depending on where you live, a radio frequency scanner might be something to get into. A scanner can be set to listen to various frequencies, like the local fire, EMS, police and public services agencies like the highway services, and of course the local airport air traffic control tower. A used scanner can be found for around $100, and there are numerous online frequency lists that you can down load for free. AS long as you are a passive listener and don't go out and rush to accident scenes or fires, you are legal.Yes!!! I never planned to retire. I quit my job to help my mom, with the intention of finding a different job(66 yrs old). After mom's surgery was over and she was up on her feet again, but I did not return to work, so I call myself "retired". I found senior centers that played cards. Senior centers are fine for weekdays, but my nights seem boring. I keep looking for stuff to do, but I haven't found it yet. I think it's the companionship I am missing. A goal. A purpose. I had all that when I was working.
People definitely should have hobbies or serious interests, but some of us were born without the hobby gene, sigh. That could then sometimes leave the serious interests, but if you didn’t get that hobby gene, all you’ll probably feel up to doing with the serious interests is read about’em.One thing I've found during my retirement really shocked me. I've found that some folks just don't have any hobbies or serious interests. I found this really hard to grasp, for I've had/have umpteen hobbies and interests all my life.