develop a crush, make sure you get really attached to that one person that a day without seeing them at school or wherever, can ruin your whole day.
make sure every time you see them your stomach hurts from how much you adore them that you feel like crying every time from how much it hurts, but yet feel so good...
that right when they walk past you, you imagine yourself having to bear with this eternal, empty, and agonizing pain, knowing that you will never be able to ever get the courage to talk to them.
cause of course why would you make an effort if you know that will only make you feel better and happier?