This bullshit starts in society and is underscored and locked in place in marriage vows, especially those which say stupid shit like "you'll never cry another tear." Nobody made you god. This same attitude goes for kids, friends, all of us. We can only be responsible for ourselves, loving to others, understanding and supportive. Anything else robs our partners of THEIR work. Their job to evolve. Of course it's hard. But that's why it is so good when it works.