What the goal of having an explanation?

Do you want the explanation to change your model of the world in a way that allows you to have the right intuition about a subject matter? Do you want the explanation to allow you to make better predictions about the subject matter?

Beliefs are supposed to pay rent.

If someone without a physics background hear about quantum mechanics they are supposed to be confused. If they aren't they would simply project their old ideas into the new theory and not really update anything on a deeper level.

emotions from biology

I'm not aware of a published theory of emotions as an extension of biology that describes all aspects of emotions that I observe on a day-to-day basis.

computers from solid state physics

Understanding hardware does need solid state physics but you also need to understand software to understand computers.