Yeah, and waaaaaaay back in the day there were actually no round limits. Naturally, as skill levels go up, regulations increase.
Also, boxers used to have to weigh-in on the morning of the fight...that was changed with the Ali act (I think). It was supposed to give the combatants time to restore their bodies before the match.
I sure wouldn't mind if top-tier title matches would go back to 15 rounds, though.