This poem says to not give your everything to certain people. Many of them are always changing and once they do, it can hurt you. It tries to explain to not get too comfortable with some people since the ending result can leave you with a painful memory.
story of my life right now."You get a strange feeling when you leave a place, like you'll not only miss the people you love, but you miss the person you are at this time and place because you'll never be this way ever again" - Azar Nafasi
Do Dishes, Rake Leaves: The Wisdom of the Ancient Homemakers
This is so, so ture! “You will never be completely at home again, because part of your heart always will be elsewhere. That is the price you pay for the richness of loving and knowing people in more than one place.