There once was a Guardian column 'Ask a grown-up' where kids could email questions they wanted 'a grown-up' to answer, Richard Curtis said in answer to 'Why does love hurt?' (what a brilliant question!) 'When they stop loving you, or you stop loving them, you lose the thing in your life that has made you most happy' This is a sentiment that most adults can identify with as, by certain age, we've experienced the highs and lows of what love can create.
I wonder though if when talking about love to a child instead of focusing on how 'another person' can bring happiness & love, would it be better to talk about a very simple but often neglected concept especially in the West, to explain the importance of loving oneself before attempting to love another person?
To love yourself to the same extent we often love another human being: Give ourselves the praise we give to someone else, appreciate ourselves, be kind to ourselves, respect ourselves, really cherish ourselves. Perhaps if we learnt to do this, the pain of a break-up wouldn't hit you quite so hard.