This has happened to me too with girlfriends, my parents, and certain compatible people through out life (teachers, coworkers, friends, etc).

There's a plot twist that no one talks about when discussing this phenomena:

If you can sync with each others thoughts in a positive way, you can do so in a negative way too.

Manipulative people are still manipulative, regardless of how well you sync up to them.

That will be the most awakening thing you can read about any of this.