This is good advice when you are dealing with intellectually honest people.

If you're dealing with a malignant narcissist, the ability to diagnose the behavior pattern is what allows you to cut your losses and run.

Professional negotiator Chris Voss has an acronym you can use to remind yourself of this when negotiating:

H.A.L.F.

1. Hard

2. Annoying

3. Lame

4. Frustrating

Whatever you're doing, if you're doing it with someone who is being H.A.L.F. then thats what its going to cost you, half of your profits, project potential, twice as much time, etc.