When you where in kindergarten, or first grade. Little anyway. Let's say you've made a drawing. You're mighty proud of this masterpiece. Let's think about the following scenarios:
1, Someone takes your painting and draws something on it.
Obviously you're heartbroken since you're drawing is now destroyed.
2, Someone draws you painting again, copying it with crayons.
This is probably not as upsetting, it probably depends on if it was one of the cool kids or not.
3, Someone takes you're picture, walks over to the copy-machine and makes a copy of it and keeps it in his or her drawer, never showing it to anyone.
Do you even care? you're a toddler.
4, Number 3 makes a copy and gives to his or her best friend.
you're getting popular right?
5, The same copy machine is used again and the kid from example NR 1 is not destroying you're drawing but extending it on his/her own copy.
Does this upset you? I don't think so, you have you're own painting still and the other kid has a new one.
So what does this all mean? I'm thinking that when we grow up, we loose a bit of common sense kids have but we keep (and expand) some of the feelings and reactions that we thought we have grown up from.