I used to have a lot of trouble when trying to not care about stuff. I didn't care about most stuff, but it used to be impossible to not care about stuff I was naturally interested in.
Now after almost three years raising a toddler I can see clearly when people are behaving like babies. And I'm used to handle a stressed baby who is not cooperating for God knows why. It happens quite frequently and I just play along. I got used to being there, offering support without any expectations (because he usually doesn't want any at that point), trying things out just to give him a chance to take the bait, etc. Now it just feels like life is finally making sense to me. I catch myself applying this to my relationship with my wife, to my work, etc. I feel like I would probably not make these realizations nor develop this mindset if it wasn't for my kid.