Okay so below I wrote literally a novel about my boxing experience haha! Part of it was for my own nostalgia of reliving the boxing days - part of it is because I feel like it has everything you can expect boxing to be - if you want to compete - and you can make your own decision off what I've said.
Story time:
I have been involved with boxing since I was seven years old. Not entirely continuously - I have gone on and off, my most recent year spurt ending ~9 months ago. In my time, I've had my fair share of amateur bouts and sparring sessions of all sorts. There is nothing like boxing, plain and simple. The adrenaline of a bout, even a good sparring session, is entirely unlike any other feeling in the world. Also, it requires very, very serious dedication to become good - even to become decent. Professional boxers, perhaps more than other types of fighters even, are super human. Fighting for 12 rounds and getting hit with what they take - I mean that's truly a phenomenal display of what the human body is capable of at its very extreme.
I was never amazing, but I was decent! Long story short I ended up getting involved with the wrong crowd at an extremely young age. Boxing was definitely part of what set me on the right path. I trained anywhere between 20-30 hours a week at times. Couldn't pay for a trainer for more than a few months at a time so I would get the training then practice in my garage, with my brothers, and with my friends all the time. If you're lacking in discipline in your life, and you need something to help get you straight, boxing can definitely help with that if you commit to it.
You can expect lots of 1-2 mile run circuits; something like sprint for anywhere between 10s-60s then run at a slower pace for 1-2min, rinse and repeat for the entire duration. If you're not a cardio person this will be simply horrible for the first few weeks, it was for me when I restarted once again this last time. You can expect lots of jump rope, 1-5min rounds, fast as you can go. Go buy a speed rope now and just start practicing; if you need to teach a fighter footwork - get them very good at jump rope. You'll want to be able to run around the track while jumping rope, string together lots of double unders, criss-cross, one foot at a time for X jumps, etc. Youtube is a good help - but in the end you'll just have to jump rump for anywhere from a few months to a year to get good.
Lots of drills too, jab step hook - for example, and variations of - over and over and over, literally thousands upon thousands of times until the movements start to become second nature. Sideways circles, defense drills, drills to keep your shoulders high and covering the side of your head, I could go on and on about all the little technical things you'll have to wire into your neural pathways to become a truly decent boxer. If the coach is good, he/she will tell you how to do everything, but you better be ready for some pain! It is a ton of fun, especially if you like adrenaline at all, and sparring will make you feel very humble - and quite possibly scared - if you end up getting into that and actually wanting to compete in a sanctioned bout. Fighting for even 2-3 minutes at a time is much, much more difficult than people think. By round 2 see if you can even manage to keep your defenses up in the beginning! 100% you will be getting hit, a fair amount - if you want to start competing it's simply inevitable.
So that's my mildly objective overview and "this is what you can expect with boxing speel". I definitely have positive feelings toward the sport and owe a lot to it, along with other types of training.
With all that said - as much as I really do love boxing, especially all it taught me and all the time spent with friends and family through it, and really how difficult and how much true dedication you need to become any good - there are downsides. I'm not sure when you might have rainbows in your vision, or wake up with weird headaches, or see a halo around every light with seemingly brighter lights everywhere you go - but if you stick with boxing long enough, you're pretty likely to get one or two of these. I did. It will probably be transient, but it will come.
That was when I drew the line. When I was a kid, sparring and what not, I didn't care about medical school - or saving my brain. Now I'm not saying that everyone who boxes for any amount of time gets long-term brain damage, definitely not. I don't have any, and I trained in the sport one way or another for quite some time. Amateur boxing hasn't been shown to cause long-term neurological damage that I am aware of either. But plain and simple, it's not good for your brain, and you'll be able to tell after you spar with some moderate-high intensity.
What did it for me was after sparring with an extremely close friend - probably someone I consider a brother, and I woke up with the brighter lights, headaches that would come and go all day, and stuff like that that wouldn't go away for a week or 2. Thing is - and if you start you'll see this - when you get really close to some of the others, if you stick around long enough - you guys will be able to spar at 100% with each other like its nothing, because your that close that you know you can test your limits with each other. And you will want to show off to impress the others too, because they are your family and your team, and your training partners - so you want to show them how well you are doing! You don't spar at 100% all the time, maybe very infrequently depending on the coach, most of the time sparring is anywhere from 30-80%. But if you want to compete, I would say its safe to assume you are going to be somewhere on the concussion spectrum at some point of your career. After a couple fights you will be much much better, and it will probably be easier, if you stick with it that long!
So that's it. That's my entire boxing experience written as objectively as possible, though certainly it is subjective, and all the little pros and cons that go with it.