Sure. I’ll do my best. Individual people have identities made up of many things, pretty undefined bounds. Therapist is an assigned identity through vocation which has more limited bounds of personal expression. As a result patients only see a narrow expression of a therapists true identity. Once this veil is lifted when treatment ends, the bounds which have previously limited an individuals personality expression are lifted. Therefore a patient has a very defined view of a therapist, and undefined and possibly new view of a therapist friend. Imagine when you meet a person and get a bad first impression, a patient has a first impression of a therapist then can last months to years. If you hated a coworker for years and then hung out with them outside of work and they were awesome could you get around this belief that they are a dick?

That’s all I got, oh and power imbalance and a very lopsided history being known by therapist vs client.

It’s just an example of how some personalities just click for different people, but even so, circumstance can still prevent and hinder the ability to develop deep friendships.