You’ve actually been applying the social psychological attribution theory for a long time now. I’m bringing it up because it supports what Mixonian has expressed many times: your ability to choose interpretations is a valuable source of power for you.
To quote Wikipedia, Attribution theory is concerned with the ways in which people explain (or attribute) the behavior of others or themselves (self-attribution) with something else. It explores how individuals “attribute” causes to events and how this cognitive perception effects their usefulness in an organization.
To make this work for you, imagine you have to make a killer presentation. That means if you don’t achieve your objective, your boss will kill you. No pressure, right?
Option 1: You could choose to attribute this responsibility to your boss having unwavering faith in your ability. Otherwise she would have assigned it to someone else.
Option 2: She’s about to fire you anyway, so in a way you’re the sacrificial victim — closing the deal is only a remote possibility.
Option 3: Obviously you’re up for a promotion, otherwise this task would have gone to someone else.
We could go on and on with other options. Motivations are normally complex and may even fluctuate. So go with an interpretation, or attribution, that seems reasonable and comfortable.