I think your mother gave you stellar advice. We don't grow up believing people will behave carelessly and still care about us. It's much easier to assume they must not care. Jennifer, you clinched it when you suggested we not remember or believe any one thing about a person or a situation. Personally, practicing this will bring me peace. Thank you for writing a much needed point of view.
The knowledge that paradoxes exist in our lives, within ourselves, our relationships with loved ones, our relationship with the world, can thrill. But once you realize it, you can't unknow it. Often we wish we could. Absolutes can comfort. Ambiguity can delight but also devastate. Great piece.