I'm not sure it's ever too late to learn anything. Unless you are dead.
But I do wish I'd been able to feel ok about my body as a teenager, the anorexia was harmful to my bones & heart, so I guess technically I learned too late to value my body, or learned it too late to avoid damage anyway, though I'm pretty healthy overall now. I think almost all teenagers are uncomfortable with their looks in some way, at least they were back then.