“No woman is old as long as she loves and is loved.” ~Vincent Van Gogh in a letter to his brother Theo, quoted in Van Gogh by Pierre Cabanne, © 1961
which is very similar to
“A heart is not judged by how much you love; but by how much you are loved by others.” ~The Wizard of Oz
but I’m not really a fan of either, because it removes control from the individual. “Loving” is an action we can choose, “being loved” is out of our hands.