I gave my kids a knife at 3 or 4. I had one at that age myself. We all got cut at one time or another.
A splash of Mercurochrome and a Band-Aid & we were good to go.
Those big garish orange stains from Mercurochrome were a badge of honor when I was a kid.
When I was 8 & a cub scout, getting your scout knife was a huge deal (actually, anything scout related was a big deal). On the days we had a den meeting, we got to wear our scout uniforms to school. Every time we got a new badge, we got to go up and stand in the front of the class and show it off.
The real big one was getting a scout knife - we not only got to wear & up in front of the class, we got to open all the blades and show it off.
Speaking of which (knives in the classroom), when I was in 2nd and 3rd grade, we started playing a game at recess with knives called stretch. Two kids faced each other with the feet together and flipped a knife into the ground be the other person. The other person had to place there foot where the knife struck, then reach down and pick up the knife - keeping their foot where it was. It was then their turn to flip the knife. That would go on until either someone lost their balance and fell down or couldn't stretch their feet far enough.
The knives we tossed ran all the way up to fixed blades in sheaths worn on the hip.
I can't even begin to imagine what that would cause today. A few hundred kids tossing knives in a field.
They'd probably call in SWAT or the National Guard.
My granddad always said, :As one door closes, another opens".
Wonderful man, terrible cabinet maker...