One of our biggest accomplishments with teaching Kendall the concept of "what's real" has been sending her "nu nu" (pacifier) to heaven for all the babies there.  It has been just over a week without them and she has been doing great.  Occasionally she will ask for them and we respond with, "Where did your 'nu nus' go?"  She always replies with, "heaven."  So I'll say we succeeded at that task while teaching her to do something good for someone else  :)