DD2 is very particular about her pull up diapers (the ones we get comes in variety packs, so it has her favorite princess mixed in with other characters not as interesting). The ones she abhors is the set that mixes in the monsters diapers. She goes through her favorites first, then next favorite and so on (her teachers have the children bring over their diapers at changing time)... until she only had the monster ones left.

Then she showed up with her favorite one instead of the despised monster one, and her teacher asked her where she got that one (her teacher knew she was down to the monster ones). Apparently she despised the monster ones so much that she was swapping those with her favorites from the cubbies of the other girls who have the same brand. (none of the other girls care at all about which diapers they have).

And I just found out that she is now calling the parents of the other children by their real names when they pick up their child, surprising them (I don't think I even know the real name of any other parent - they are all "XX's mom/dad" to me).