I'll Never Wrap Leftovers The Same Again!

So how many leftovers did you wrap over the holidays?  You have your plastic wrap, your foil wrap etc.  You pull the stuff and the roll pops out of the top of the box.  I just discovered there is an easy  way to avoid that!

If you look on the sides of most wrap boxes you'll see this.

You push it in on each side and it keeps the wrap from popping out of the box.   Am I the only one who didn't know this?   Mom why didn't you tell me?  First the whole birds & the bees thing, now this!