The act of sharing is free

Sharing is a fact of life isn't it?
We are constantly sharing with family, friends, co-workers and strangers.  Sometimes we share an experience,  maybe to help someone going through a difficult time.
The act of sharing is free and makes both the giver and the receiver feel valued.
It is especially difficult for kids to grasp this concept.  Although,  I have to say some adults I have encountered still need some practice. 

Here are my two bunnies sharing pencil crayons,  space at the table, and each other's company.  This little 'moment' lasted, oh... about ten minutes before they could not share any longer.

What do you have a hard time sharing?