Collective Responsibility
Right from birth humans know that they cannot survive alone and on their own. Babies cannot live without the care of adults. If our only concern is for ourselves, we are shirking a basic human need, that of being loved and of loving others. Loneliness is a great sorrow, but sharing time or things is life.
All of God's commandments for how to treat other humans are summed up in "Love your neighbor as yourself" (Matthew 19:19). We always have choices, but often with no further cost to ourselves. We can help those in need of help. We gain warmth from a fire and fill our need while we also can offer a warm place to others. All humans were created to be social and have a responsibility to someone other than the self. That is the source of contentment in life—caring for the self as we care for others.