Even incorrect mental models can be useful.
My cat, for example. She knows that if she stares at a door for long enough, it will open and she'll be able to pass through. She probably doesn't understand that a human opened it, and she may well think that she caused it to be opened.
The mental model is still useful. It's still effective, even if my cat thinks that she somehow willed the door to open (in which case she'd be incorrect), the door opens and her goal was achieved.
Next time someone (or even you) get something wrong, it may not be too much of an issue. The key thing is to acknowledge where the gaps in your knowledge are... If we can have a functioning model, even if it has some gaps, we can achieve so much more, so much faster than if we wait until fully understanding some domain before acting.
This also can backfire, however. So always, always, always be concious of your model's limitations.