Solipsism.

If your mind doesn't exist, then what word do you use to describe the sum of the experiences you are experiencing and your awareness thereof? 

I assume that what we commonly refer to as reality is more or less real (mostly as a convenience) but if it is not then language also is not and creating designations for things becomes nonsensical.

Unless you are unwittingly the demon.

then the question is begged, from whence comes my mind? 

Loaded question: it presumes it had to "come" from somewhere. Perhaps your mind is eternal. The only thing that has existed and the only thing that will ever exist, fabricating a universe of causes and physicality to hold onto some semblance of sanity or, perhaps, as a symptom of insanity.

That introduces the problem of personal identity then. My experiences started a finite span of time ago, yet an uncaused eternal mind ought to have no beginning nor end. My mind is therefore subject to the passage of time and not the source of it.

Did it though? How can you be objectively certain that time is actually passing? You can only ever experience the moment you are actually occupying and this one moment may be infinite, whichever moment you are experiencing as you think about this.

How can you be sure that your experience isn't just an infinite loop replaying your "life" like a metaphysical TiVo over and over for eternity (or whatever passes for it if nothing exists)?

The problem with objective certainty is that it may not exist.

You need a shave with Occam's razor.

Suppose all my memories up to this point are fabricated memories and all I'm experiencing is the current moment over and over again. This doesn't match up with my experiences, so it's not a part of my experienced reality. It's not so much the case as I can't prove that I'm not hallucinating my memories as I can't prove I am hallucinating when all reason points to my existence being real.

if you doubt the ability for your mind to form a single valid conclusion a priori then you have formulated a contradiction and it isn't true. 

also thank god it's a mutually exclusive dichotomy. Either truth is knowable or not truth is knowable. Not truth is knowable is a necessarily false claim ergo truth is definitively knowable. 

law of excluded middle.

I'm not putting a probability on this just acknowledging the impossibility of ever being certain. It is convenient to accept reality at face value, but even if we do we still are not experiencing reality directly but instead experiencing the mental picture our brains form of it.

Aren't you faced with the same existential quandry?

nah I'm contesting the impossibility of certainty. I've made the claim that it's impossible to be uncertain about everything, because you would need to be certain that there's nothing you're certain about. 

There is only one thing I am certain of. I am experiencing something even if that something turns out to be totally illusory. I didn't claim to be uncertain about all things only all things besides that.

To claim that that is a true claim is actually two claims. You're certain of two claims. But that's a third claim. Ad infinitum, you're certain of an infinite number of things.

We could conceive of a different kind of eternity, then. Instead of a line extending infinitely in all directions, a "loop" that resets and repeats. Always has been and always will.

I suppose, although we still get paradoxes like Hilbert's hotel imho, the classical impossibility for an infinite regression of events in reality. Also if it is the case that my mind is self contained via my minds memories, then why don't I have memories of my mind from millions of years ago?

Imagine your life as a movie on a movie reel, except the end of the reel is taped to the beginning, so that it repeats and continues endlessly. Your your entire life exists as a whole on the reel. The only real question is why you perceive yourself as existing in this moment as opposed to any other.

It still just amounts to the fact that I am experiencing something even if that something turns out to be totally illusory. Math does not bring you any closer to knowing if your experience is genuine or illusory. I don't care if you do realize that you realize that you realize that you realize that you realize that you realize that it might be illusory.

The concept of experiencing "reality directly" apart from our senses seems to me to be an incoherent concept, an impossibility for anyone or anything. Your senses are experiencing reality as directly as anything can, just from a different perspective than anyone or anything else. In your concept of experiencing reality directly, one would need to be able to perceive a thing in all of it's forms from every position and perspective possible. A thing can be perceived from a physical distance perspective, from a frequency perspective, from human and non-human sensory perspectives, etc. Even if you were able to perceive every electron and quark making up a thing it would just be another perspective which excludes other perspectives. Unless you are able to experience all possible perspectives (which would be infinite) then the concept is incoherent.

Your mental picture of a thing is a way of experiencing reality directly.

You are probably more concerned with perceived "accuracy". It seems impossible to verify and I am happy to accept my perceptive accuracy as "good enough". I have no need to be solipsistic about it.

If what we perceive reflects reality in any meaningful way you are correct and it is convenient to behave as though they do but we must start with a presupposition in order to do so.

I behave as though everything I perceive is reality because even if it is not necessarily real it is the only "reality" I know. This does not mean however that I must be correct.

In any case you are never really directly experiencing anything. You don't see a base ball yourbrain constructs an image of the base ball based on the amount, frequency and direction of light rays striking the cones and rods in the retina. This image would seem to be emergent from chemical reactions and electrical patterns within the brain itself.

These brain states are all you ever really perceive. Ever.

There is no perceiving anything directly. Ever. Not for us as humans. There are only the brain states.

Then what do you mean when you keep saying that we are unable to "experience reality directly"? That is like saying we are unable to be unicorns. It doesn't mean anything.

Yeah that's philosophy. A lot of it is useless crap. It doesn't actually make a functional difference from my perspective whether or not the universe as I perceive it is real or not. It doesn't inform my descision making process in the least. It is however beyond my epistemological limits to say with certainty that it is or isn't real.

I suppose it depends on what you mean by "real". Even a simulation is "real" from at least one perspective. It is not beyond epistemological limits to say that the universe (defined as all that exists) is real.

Perhaps you mean that your perception of the universe may not be accurate. In my opinion, that sentiment is meaningless and useless.

There is no particular reason to believe that anything does exist besides my perceptions themselves. If you prefer I could say that the universe may consist of nothingbut my illusory perceptions. Would that satisfy the semantics problem we seem to be having?

Not really. Perception implies an external phenomenon that causes your mind to create an image.

You could say that the universe may consist only of the hallucinations in your disembodied brain. That makes as much sense as any other solipsistic notion.

The whole point is that we don't really know.

My point is that we do know - from our own perspective. It just can't be proven with 100% certainty. To say that one doesn't know anything is philosophically meaningless and functionally useless in my opinion.