One. Criticism, and how it differs from a complaint

A complaint is about an event. You did not call and I was worried. That is fine. Marriages need complaints.

Criticism is about the person. You never think about anyone but yourself. Same starting incident, different target. One of them can be answered. The other one requires the other person to defend their character, which nobody does calmly.

The tell is usually a word like always or never, or the phrase what kind of person. Once you hear it in your own mouth you can hear it everywhere.