Friend: calls your parents by mr. and mrs.
Best friend: calls your parents by their first names. 
Friend: has never seen you cry 
Best friend: has always had the best shoulder to cry on 
Friend: never asks for anything to eat or drink 
Best friend: opens the fridge and makes herself at home 
Friend: asks you to write down your number. 
Best friend: they ask you for their number 
Friend: borrows your stuff for a few days then gives it back. 
Best friend: has a closet full of your stuff 
Friend: only knows a few things about you 
Best friend: could write a biography on your life story 
Friend: will leave you behind if that is what the crowd is doing 
Best friend: will always go with you