Theory of subjective reality

Mind boggling. What an interesting term. Because in essence, the mind is what it comes down to, isn't it? The very basis of our existence, the fine line between being alive and being dead, everything about who we are, what we do, what and how we feel, every sensation, notion, perception...finally comes down to a hunk of mass in our cerebral chambers.
How do we know, if what I really see when I see the color red is the same as what someone else sees? How do we know our perception of the taste of chocolate is exactly the same as the next person? How do we identify, describe, pin down these intimate sensations when the truth is that everyone's world is so subjective?

Lets say I see a river. It calls to my mind childhood memories of days spent in a village (err..lets assume I DID actually spend days in one). The sound of the river, the touch of water droplets against my skin, the sight of ribbons of foam gliding over rocks and colliding with each other, these are all sensations very real to me. But these sensations are also linked to past memories of running through mango orchards, fishing in a stream, and suddenly a myriad smells, thoughts, memories come flooding to me. And yet this entire experience is and will be completely different for each person by that river that day. So what does that say about the reality of that river? Yes, it exists, and yet its reality is completely subjective to each person. There is a world inside "me", and a world outside "me", and each influences the other.

And if that is truly the case, how real is our reality? Who is to say a colorblind person's perception of color is any less "real" then ours? Who's to say a schizophrenic's hallucinations are any less real then our daily sights and sounds? (ps..highly recommend 15 Park Avenue). If reality is as real as our perception of it, how is it to be defined? If a person with phantom limbs can feel and sense their defunct organs, which means they still exist in their mind, does that make them real? What about ghosts, alien sightings, dreams? Do they count?

If I imagine myself on a vacation to Rivendell, does that qualify as reality?
Ok I might be pushing it. Some Elven bread would be nice though.

Once we start questioning the non-dual nature of reality, there is no end to the Pandora's box it opens up. If in effect, every feeling, thought, emotion, cold, hot, depression, obsession, gravity, beauty, love, God, finally comes down to a jump of protoplasm, a shoft of a neuron, a precise chemical paradigm shift, where does that leave us? We, the allmighty superhumans, who believe ourselves to be so very significant, do our lives just consist of going through the motions?
Are there some evolved four-dimensional creatures out there somewhere looking at us with mild amusement, shaking their heads going "what losers, do they think their lives actually mean something?", sort of the way we look at armies of ants going about their business.

Hmm. Thinking about thinking about thinking has my mind completely boggled.