It's common to start therapy in a place of self-discovery where we are not all that sure about what it is that is "wrong" and where that wrongness even stems from. So, it's no surprise then that we might also come into therapy with beliefs or fantasies of what therapy will do for us.
Some common ones i've see a lot of are:
The belief that healing will lead to a state of sustained happiness.
That healing means no longer experiencing "bad" emotions such as sadness or anger.
That we will be above getting activated by people, particularly the same ones who caused our wounds in the first place.
That we'll have the ability to tolerate more pain.
That we hold the expectation of perfection.
Being healed means we should let others off the hook when causing harm to us, that we should "rise above".
That we will fully return to a pre-trauma baseline or becoming an ideal version of ourselves.
If you feel like you've been getting tangled up in your progress, you may want to explore some of your own.