I also like exercising. which includes working out and martial arts. I like laying some kicks on my punching dummy named BOB. I also snowboard, hike, and fish
Mine... a little woodworking, although got away from that for awhile due to being busy with family, but will be getting the shop back in service soon. Metal detecting, something my wife discovered and now something we share. The only other thing, I collect is the small (matchbox/hot wheels-size) ambulances.
I never thought of exercise, (in my case running), or even relaxation; as a hobby. I always envisioned them in the category of physical and mental well being, basically because they maintain the health of your body. To some, it can be a necessity; to others a preventative or just good common sense. I guess I can add running to my earlier list as well.
Do unidentified flying objects exist? Not necessarily "flying saucers", simply items that you--the observer--cannot readily name? If so, then yes, UFOs are non-fiction.
"Do you know of any other hobbies that rival ours?" Nope. But, there are other hobbies, just not as good.
A little side hobby of mine as well. I have liked tractors since getting to operate a crawler to take out some trees when I was about 4-5 years old. My favourite models are the Cat Crawlers, would like to find one of the Benjamin Holt models of the steam era tractors sometime.
I just Googled popular hobbies & got this list. Coin collecting did not make the top 50 but somehow "dating online" is a hobby. Reading was actually #1 in this list but it didn't copy properly. Watching TV Family Time Going to Movies Fishing Computer Gardening Renting Movies Walking Exercise Listening to Music Entertaining Hunting Team Sports Shopping Traveling Sleeping Socializing Sewing Golf Church Activities Relaxing Playing Music Housework Crafts Watching Sports Bicycling Playing Cards Hiking Cooking Eating Out Dating Online Swimming Camping Skiing Working on Cars Writing Boating Motorcycling Animal Care Bowling Painting Running Dancing Horseback Riding Tennis Theater Billiards Beach Volunteer Work I personally enjoy fishing, boating, music & theater. I also enjoy travel which is evidenced by all the stamps in my passports.
As well as coins I collect WWI and pre WWI war medals. I also collect and deal in antiques and post on the sister site. https://www.antiquers.com/forums/
I also collect tin toys and political campaign items. But as far a hobby that rivals our passion for collecting coins I think my wife's "baby wearing" hobby is on par. She's on like 4 or 5 forums and tons of FaceBook groups. She probably spends more time per day on her hobby than mine. Although it can't last too much longer since our daughter is six months.
Although coin collecting is my favorite hobby, I also like to collect non sports cards such as Batman, Tarzan, and Star Trek.
I collect coins, old interesting bottles, guns, money, and historical items from my fraternity that are no longer available. Those are material items that I actively collect, however I enjoy physical activity as well and usually like to: hike, boat, fish, run, swim, shoot some hoops, work, and spend time with my friends.
My obsessive collecting started with my fraternity stuff. I was buying books, magazines, pins, jewelry, manuals, etc. At this point I have nearly enough information/material to work on writing our 125th anniversary history book (which is a very real goal of mine), and doubt there are many other similar collections in private hands that could rival mine. To this day I am still the main purchaser of anything rare or interesting that turns up on ebay or amazon.
Well I could mean literally what UFO spells out, and that doesn't have to mean little aliens flying in them or controlling them remotely. Things fly up there without being identified all the time. It's empirical, therefore not fiction. Even the govt's own official studies showed that a significant percentage of reports thoroughly investigated were unidentified. However, I tend to think otherworldly intelligence is involved in UFOs and other unexplained phenomena--ie abductions.
The only way a hobby could rival coin collecting is if it was equal or greater in popularity, completely free and offered a superior variety of subject matter. The only thing close to that description are crown caps. Breweries already engage these collectors with freebies, just pay the postage. Any kid on the globe, even third world and homeless can find a place where the local drunks hang out (park bench, under bridge, etc.) and pick up a variety of hobby starters. I've never considered it, but, I have a friend who likes coins and crown caps. These guys are pros, with pages, binders, drawers, cabinets, etc. The items I've ordered for this friend include entire sport team crown cap sets in hockey, football and olympics. This hobby is huge.