And then, after running experiments that demonstrate invariance, physicists go home, or to a bar, or to a reunion, and when they do, they enter another kind of universe, one in which variance is the law. People don’t work the way the physical universe works. Yes, there are definitely two universes: A consistent physical one and an inconsistent social one.
Variance is the law in social relationships, so seeking invariance in a partner is a fruitless quest. No such law applies to people naturally. In the experiment called life, one needs to recognize that loved ones, life partners, and acquaintances change. As in any physical mutation, social or personal variance takes on one of three forms: Some mutations are good for a continued relationship; some are neutral, and some are detrimental. When people recognize the inevitability of change in others, they have choices: Accepting change; rejecting change; struggling with change, neither fully accepting nor fully rejecting it; and ignoring change until if forces its way like a magma chamber onto the surface in a volcanic eruption.
Demanding invariance in social relationships is like demanding that hammers dropped by astronauts don’t fall toward the moon’s surface: Neither demand can be fulfilled without overturning the laws of their respective universes. Variance is the universal property of human existence. Learn to deal with it in the lab of life.