Ok so you are a man living long long ago before science books or before anything labeled, science.What does that even mean -- "without science"?
learning how to learn
are all basic tenets of science. All of which are related to "evidence", "documentation, and "data".
You can't prove something without actually participating in any of those skills I listed. So what exactly to you expect us to even do here?
If you asked yourself "How do I know I am real" "How do I know I exist"
"How do I know this life is real" What would your answer to yourself be" ?