You know how they say "kids are resilient" but really it leads to them needing therapy as adults?
I'm convinced a lot of the random physical pains of old age are the delayed effects of those childhood injuries we jumped up from and immediately forgot.
A buddy of mine was talking to his doctor not long after he turned 50 and he was complaining about some random pain. The doctor told him "You know all that stupid stuff you did when you were younger? That's what hurts now."
Partially so, but a lot of adult pain is due to bad posture, and weak muscles from lack of exercise. (Weak muscles don't directly result in pain, but it does mean that stuff like "looking in the mailbox weird", or sneezing, or lifting something off the floor can result in stuff going wrong.)