as we grow up, we learn that even the one person that wasn't supposed to let us down probably will. you'll have your heart broken, probably more than once, and it is harder every time. you'll break hearts too, so remember how it felt when someone broke yours. you'll fight with your best friend and maybe even fall in love with them. you'll cry because time is passing too fast and you'll eventually lose someone close to you.
so..
thats life :P

(i've decided to write the word 'you' in the right way, and not 'u' - but the rest will be written in a relaxed kinda way.. slang-pang)