@alitanha,
You might be a Universe unto yourself, all your "knowledge" and "experience" and "beliefs" just a dream constructed by your own consciousness. You might be the one and only thing in existence, alone and dreaming forever. That was the premise of "The Mysterious Stranger" by Mark Twain.
Nothing can ever prove those types of conjectures wrong so they can't be ruled out. But I'm not sure they are of any value, other than to recognize that they exist within the realm of possibility (if not probability), as does everything else.