I use to hear that all the time growing up. I wasn't much into sandboxes and if someone tried to take a toy from my brother, I was there to save the day, recover the toy and make sure whom ever took it in the first place was made very aware it was not going to happen again.
As I grew up my brother needed less protecting, but I still hear my Mom yelling at times "Play nice in the sandbox"! I usually heed the words, but today I didn't feel like playing nice in the sandbox, in fact I found myself going back to the old days and wanting to "make someone very aware" that I wasn't going to put up with the taking of the toys!
It was a feeling I don't get very often, but one that makes me very aware of my hidden temper as well as my ability to manage myself through it. It is hard though. Really it is. When I see things happening to others that just aren't right I want to 'take back the toys' and make them very aware that it will NEVER happen again.
The good news is that I didn't take any toys or make anyone aware of anything as I stopped and thought of a better way of handling it..it worked. It didn't seem as fun as throwing sand but you know what you happens when you throw sand...most of it flies back into your face.
There are times when others will remember us not by what we do, but by what we don't do. To throw or not throw...Play nice in the sandbox.