Just my confusion

Everybody have to go through changes in life.But why do we have to change ourself for the society or for anything else for that matter.Specially the person you love and believe he/she will be the same forever changes like a spontaneous emission and there the confusion starts.We go through different stages in life.Meet new people have new life in each walk of life.But is it necessary to forget what we are what we do.Or is it the society which changes and brings out a total new person.Some totally forget and as they leave the past behind forgetting everything.Some do it as a duty to keep in touch with the people you have been with.Why do they have to pretend?Why do they have to give a confidence that they will be there forever.Why do they have to lose interest?Do all those people ever have a minute to think how memorable everything was in the past?There are so many "WH" questions i can keep posting for the sake of blogging but am sure i know this is the truth of life and i should accept and move on in life which i dont want to...