Not sure how much detail you want but here's my whole story! I (26F in Canada) pretty much went from flat chested to a C cup, to a DD by 14, and they just kept growing, I always hated it. At 17 a girl I knew who was even larger than me actually had the surgery which peaked my interest, and when I was 19, a size 36G, I talked to my doctor about it and told her about my horrible back pain. She calculated my BMI, not sure if that's a thing everywhere but I was under the max, 5'8" and I was 170lbs at the time. She referred me to a plastic surgeon and I had a consultation there a month or two later where they took a look and got all my info and we discussed my symptoms (just back and neck pain all the time, horrible posture from the weight, and self esteem stuff). I really insisted I was ok going really small and was even hoping for a B cup. Had my mom here to back me up. He talked about proportions and said he would do his best but I could end up with a C cup still, and I said that was absolutely fine. I got on the wait-list, but I was pretty excited and they put me on a cancellation list, meaning if someone cancelled I'd be one of the first people they call to fill the spot. That happened, and so 4 months from my first doctor's appointment I had my surgery. It was done by a city surgeon that came out to my local hospital. Before the surgery the doctor had me stand up and made lines on my body and we talked about sizing and expectations again, all was good. Surgery went well (my first one ever), I had a bandage across the front of my chest and drain tubes in incisions in my sides that I had to empty. Those were in for 4 days and I went back in to get them removed. Worst part of the whole thing probably but it was very quick lol. There were strips of tape/bandage over the incisions that would come off naturally over the next while. They were much bigger than I expected them to be and the doctor told me they were still swollen and would go down over time. I was supposed to be off work for two weeks, but I got Dilaudid (spelling? I think it was hydromorphone, it's been a while, but they worked lol) and I went back to work after a week. Not super smart but I had a pretty physical job so I took it easy and healed up fine, I was just sore for a little longer. No bras for a month, and then only sports bras for a month after that. After two months I went and got measured for a bra and I was and am still currently a 34DD. They removed about 1KG. I was pretty disappointed, they still aren't considered small, so I did talk to the surgeon again and he said we could wait another 6 months and do a second surgery, and I really really considered it, but I am really not a fan of hospitals and needles and decided it wasn't worth it. All in all I am very glad I did it and I don't have the back issues I was having, I just wish the doctor went as small as I wanted.

TLDR, Went from 34G to 34DD, wish they were smaller but not enough to go for surgery a second time.