Recently my 18 year old brother's best friend died of undefined causes whilst abroad at the beginning of a gap year in Germany. He had literally left school two months ago and his life was only just beginning.
It just reminds me how fragile life is. It is so easy to think of our young selves as immortal, untouchable by illness or anything else.. But we are not. Any tragedy can happen at any second. Just make the most of your life while you have it and still can. Do what you want to do. Love who you want to love. Experience everything you want to experience. Don't waste it and don't wait because it can be taken away at any second. And remember that the only thing, if you lose it, that you will never ever be able to get back...is time!