Squash yourself down. Hide those parts of yourself that are different from others, cut away anything unique that may be a target. Become grey, brown, muddy, same.
Ordinary is safe. Ordinary is invisible. Ordinary gives you the reflexive knee jerk approval of the crowd and the dismissal from their collective minds. Ordinary allows you to move unseen through life. Nothing to see here, nothing to attack here, nothing to celebrate here.
Don't stand out. Don't reach to the stars. Don't grow tall, the normal size poppies will cut you down. Hide your light, though the pressure builds inside. Make small talk only; hide your desires, your fears, your cares, your dreams. You are ordinary. You are normal. You are boring. You are safe.
Get through school. Get through your first job. Get older. Realise you are unhappy. Eventually realise that absolutely noone is ordinary, and that those who appeared ordinary for so long were simply hiding parts of themselves all this time too. Realise that it's ok to be different. Realise that it's ok to have dreams. Realise that other people's opinions are their own business.
Start working toward your dreams. Don't lament the years wasted pretending to be ordinary, lest you waste even more years in grief. Do the things that make you happy. Allow yourself to stand out in your own way, and celebrate the things that make other people stand out. Create a space in the world for yourself to occupy and fill. Do the little odd things that bring you joy. Pursue those hobbies you were always curious about but never dared attempt. Share the deep part of yourself with other people and hear them respond in kind. Make connections, have hope, feel satisfied. Feel like you finally fit in your own skin.
I don't think that there's anything worse than being ordinary and cheating yourself of experiencing who you really are.