To get a bigger slice, someone else has to get a smaller slice.
The world is a competition for the biggest slice.
Some people miss out altogether as the greedy take more and more. even though they couldn't possibly eat all the pie they've taken.
Hoarded pie goes to waste while others starve.
If I light your candle with my candle, nothing of mine is diminished and the light gets brighter for both of us. The more candles we light around us the brighter it is for everyone even those without a candle at all.