It is so true... then plan your time with or without them for the rest of your time... being sure not to waste time on the selfish faithless ones. Let go and let God... or rejoice in true friendship/family.
I've observed this one time and time again. It has made me a bit pessimistic about friendship, but it has also made me absolutely delighted by a couple of family members who are my best friends ever. Always have been, always will be.