system
Given the following post, respond as if you're commenting on Reddit:
human
[My Hero Academia] Was All Might aware that Izuku using One For All AT ALL in the early arcs was going to practically obliterate his body from the inside-out? And he didn't think to tell him?

If so, dick move. It's established that if Izuku does that too often he'll end up permanently damaging his body and ruining his hero career before it even starts. Plus he's like, 15.
gpt
All Might and Deku had significantly different circumstances when they inherited the mantle of One For All. When All Might obtained it, he almost instantly mastered it, able to use it at 100% power with no obstacles, at least according to Gran Torino. Deku wasn't that lucky and had to learn how to control it from the ground up.