Can be many things.

Entitlement and/or expectations, I think, mostly.

I try to avoid both of them, but it's easier said than done.

Especially the expectations part. I've expected people to be honest with me. I've expected people to respect me. I've expected people to support, or at the very least, understand me. In the end, it doesn't really get you anywhere. Sooner or later, the expectations are not met and disappointment follows in its footsteps.

Our problems tend to arise from the moment we think we deserve something.