Drifting Apart Quotes

He started to estrange her... And they became strangers Who knew each other's heart, So broken as they drifted apart.

A small world where people know each other, and still so deep, able to get lost.

I think it was C.S. Lewis that asked, 'Do not most people simply drift away?'. I've always been a reader and for the longest time that stuck with me because I was at war with it. How can people 'simply' drift away?