But, if everything exists within our minds how could one explain things which should be unknowable based on one's limited experience? Is the only two alternatives then that: 1. Reality is not just within our minds... 2. If reality is within our minds, then our minds are much more expansive than we are led to believe?
Give an example. You only know things based on your senses anyway. This is basically what Decartes, Berkeley, Kant, etc were interested in. Kant actually wrote a lot about ethics too, but he began with that "how do we know what's real" question.
We don't know what's real. That's my point. The issue is how much "encompasses" reality, if you know what I mean. Like why do some people live "normal" existences completely unaware of X, Y, and Z, while others have extraordinary realities/perceptions since they were young?