Remember: there has never been a single fact, theory, or model that science has been able to prove beyond all doubt, and as long as the scientific method is utilized, this will remain the case forever.
Science can't prove shit. Never has, never will.
I know enough to know that I know nothing at all.
I'm sorry, but I think that's a stupid thing to say.
Of course you know things in some context or another, and you even know things absolutely in some context or another.
You know you exist in the context of your experience. If you don't, you're insane. It's directly evident -- so evident, in fact, that you know this before you could even generate the electrical signal to generate the thought in your head that you know you exist.
Direct experience. i.e. a direct subject/object relationship begets absolute information (and thus, absolute knowledge) about that relational system. It's there. All you need to do is stop being insane and acknowledge it.
I'm honestly saying this respectfully, because I've said your exact words in the past...until I realized they were insane.