>>82283254 (OP)
Similar boat.
At a minimum I wish I had been much more physically active and ate a healthier diet as a child and adolescent.
I'm sure I cost myself (based on parents' and sisters' height) at least an inch or two of height, and worse overall development of my frame, by being completely sedentary and overweight, and eating a shitty diet, as a teen.
I sometimes fantasize about going back in time and "raising" myself so I turn out differently.