Good question, actually. As a kid I had no idea I was totally into science, though I was experimenting all the time.
I'll always remember that day, when I discovered the centrifugal force. I was supposed to just hold the shopping basket and stand still in our garden, while waiting for my mother. Well, I wasn't able to stand still. Instead I prefered to spin the shopping basket around. Faster and faster. When I stopped it, I realized that it still contains a few pebble stones. How was this possible? Was there a limit for the number of the tiny stones? Why didn't they fall out of the shopping basket? I needed to find out how this miracle works. So I tried this little experiment a couple of times. With the following conclusion:
-) you have to spin quick enough
-) the pebble stones should be tiny enough
-) don't you ever use to much of them
-) otherwise.... better wear a hat and glasses ;-)