This idea has been going around for ages. It still proves to be true. Things that happen repeatedly eventually loses its impact. Let's use as an example a recurring disappointment or a wish that you keep hoping for. If the same things happen over and over and over again, they gradually begin not to matter.
It's really like filling a glass with water. Once the glass fills up, all the water you keep pouring in it gets wasted.
I now feel that it's futile to care for some things that shouldn't matter anymore. Let go. Let it slide.
I'm beginning to think that maybe, just maybe, there's a limit to that human capacity to care.