vf.nightcore said:
I'm really starting to wonder, what is reality even?
Be very specific. It helps clarify what you're asking and forces us to come up with better questions. What is reality is just too generic.

I mean, I am me and you are you, but it's all in our minds.
Yes. But that doesn't make it less real. Understand there's also the world that is not the mind, not in the mind, not a product of the mind. Just know the difference.

The body is just a device designed to carry us around.
We don't know what the body is or how it came to exist as we know it. Just like the rest of life & biology.

We shouldn't make such assumptions if we ever want to understand the body and life better then we do right now.

So in theory, can't we just change reality to fit our needs?
Yes. Aren't we doing that already all the time?

Or is it a mix of reality and fantasy, if so it must be possible to travel to other dimensions.
I don't understand why you say it's a mix of reality and fantasy because it isn't. There's reality, there's the human experience and there's humans that are adept at imagining things but that's about it.

Occasionally an individual becomes very preoccupied with their fantasies and I call that escapism.

Besides maybe unhealthy, being preoccupied with a fantastic story that was never real isn't the same as changing your reality to the fantasy you wish it to be. So I advise knowing the difference.