Dreams of forgotten seconds and the man who lived alone

So, I got thinking.
If no one else is aware of something, how can you prove it's physically there? You can not. How can you prove it's mentally there? You can not.

Example 1.
A man lives his entire life alone, not a single living person knows of his existance, and he creates something, in a room nobody has ever seen. To the world, he does not exist.
Now, a few questions arise.
A) Would anybody be able to see the thing he created?
B) Did the man ever really exist?

Considering no one ever knew of him, no, he would not exist to anybody, and if nobody else existed to him... Well, no, no one would be able to see his created thing. It's not there, without the knowledge that it exists, ithout any proof of someone creating it, and without any ideas he would have of someone, ( though no one existed to him, he was alone, the only man), no one could ever see this thing. And even if by some miracle they could see it, the man would still not exist.

Neo says, "There is no man".



Now, to further express the point I'm getting at, have you ever seen that film about all the children going missing and no one remembering that they existed? One woman, trying to prove there were children, but memories have been re-adjusted.
How cn you prove everything you rememeber actually existed?
We are aware there is no present time. Every milli-second that passes is the past, every milli-second that is approaching is in the future. You can never hit the exact point of anything. It's always coming, or gone.
So, how can you prove anything, when the exact second is never there, and all memory could've just been inserted and re-adjusted? You can not. Which shows, you can not even prove your own existance.
'I think, therefor, I am'. So, if someone else was sharing your mind, could see all memory, could create thought and influence action, how are they not you?
There is no way to prove anything, which brings us back to 'how can you prove anything if no one else is aware of it, and how can you prove it's in your head?'
No way possible.
You may not be you. You may not exist. And even if you do, how do you know I do? How can you prove you are not dreaming?
In your sleep, in your dreams, you have memory, right? While dreaming, you feel pain, have thought, have memory, what is the difference between reality and dream? More importantly, how can you TELL you're dreaming, while dreaming? How can you prove you're not asleep right now?

Unanswerable, right? No proof.
Fallibilism.