Friend is one, who (F)inds you in a (R)ush of people, (I)nspires you to do something in life, catch your (E)motions and (N)ever leaves you till (D)eath.
People never know how special someone is until they leave, but maybe sometimes its important to leave, so they are given that chance to see how special that someone really is.
We cannot tell the precise moment when friendship is formed. As in filling a vessel drop by drop, there is at last a drop which makes it run over; so in a series of kindnesses there is at last one which makes the heart run over."