[...]We had metal slides, we walked to school, we skinned our knees on the pavement and we fell off our bicycles and SURVIVED!
[...]You need to hurt yourself a little bit so you develop the common sense not to eventually do something moronic and hurt yourself A LOT.
I do agree, except for the seat belt thingy. You'd be surprised how horrible the injuries are even at such a low velocity as 12 mph.
When I was a kid, seat belts for normal cars were not invented yet. Only racing cars had some. IIRC the first ones in normal cars turned up in the 70s. Today I feel naked without a seatbelt.