I can't say the concussions as a kid helped any. Probably the reason why I had every conceivable ADD symptom for 40 years. But I do think the scrapes and bruises and gashes really do a kid some good.
Cracks me up every time I see a parent rush to help they're kid before they're even crying. Honestly, I always looked away for a second if I saw my kids fall down, just so they wouldn't milk it. Trust me, if they're really hurt, you'll know it, and then you can help bandage them up! By the time my oldest son was in junior high, he had made his own triage kit, a box filled with bandages, hydrogen peroxide and first aid tape.