Yes, I know - you're missing the point I'm making. Adults brains are less likely to go shake the sign, as it might break and that would have major consequences.

Yes, I know - you're missing the point I'm making. Adults brains are less likely to go shake the sign, as it might break and that would have major consequences. The kid doesn't know this, and it's also less likely for major issues to arise, so the situation is different and we generally don't get upset at kids for shaking the sign. The OP said that the sign in their story was shaking "uncontrollably". That word means something here - it means the sign was really shaking. Adults don't normally do that because it carries a real, physical risk both in damaging the property but also harming another person. It's not just innocent play for an adult to go shaking stop signs on the street - it's downright dangerous. My point is that it is a good thing that adults don't go around shaking signs. We shouldn't be concerned about not being kids anymore just because we have the maturity to know about risk and health. It's not a bad thing that we know it's not acceptable to go around shaking signs uncontrollably.