Writer in the United Kingdom
I started boxing at school when I was 11. I loved the sport from the start. Our instructor was an ex-army boxer whose aim was to "toughen us up". I was lucky to start young because we learned how to give and take punches before we were strong enough to do serious damage. By the time we reached 17 (as in the picture) it got a lot tougher but by then we were ready for it.
We had no head guards and light gloves and we fought 3 x 3 min rounds from the start. If you didn't do well you'd get sent straight back into the ring for another 3 rounds. It was a great start. Later I found a club where I could do 10 or 12 round fights and I loved them for a while. We even had occasional 15 rounders. My last real fight was when I was 37 and I loved (almost) every minute of it.
I was never tempted to go professional, even if I'd been good enough (which I wasn't). I was too interested in science for that. For me it was a sport that gave me a lot of pleasure. It's something you should do because you really want to: being paid to fight would have spoiled its value.
During the 80s, head guards and big gloves came in but boxing lost popularity. It's been amazing to me to see the huge resurgence in combat sports in the last decade, especially MMA. The reaction to excessive safety rules was to increase the length of rounds to 5 min and make the gloves a brick-like 4 oz. Muay thai and MMA barely existed when I was boxing, but if were starting now, I'd certainly want to try them.
The other big change is the huge number of women who now compete. When I saw Regina Halmich fight hard for 10 rounds it was obvious the world had changed. I think women have done a lot to counter the thuggish image of combat sports outside the ring or cage, though inside the ring/cage they fight just as hard as any men.
My view of martial arts can be found at https://undertheropes.com/2016/04/18/good-toughness-and-bad-toughness/
After I got too old for boxing, i moved on to sailing, marathon-running and ice-swimming. And when I got too old for them, mountain walking.