You know you exist, but how sure are you that I exist? That if you saw me walking down the street, what you think of as me wasn't made up in your mind along with everything else you see?
"I think, therefore I am, but you probably exist too!" is not what Descartes Said. Funny thing about that adage, its implication is that you don’t exist... or I don’t exist, depending on who’s perspective we are talking about.
The problem is that thoughts cannot be examined in any meaningful way by a third party, well at least not yet. So our conscious awareness of our own existence is confirmed only internally, “I think therefore I exist”.
But what does this all mean to you? Well I can’t speak for you but to me, not much. the pursuit of absolute truth through the rigors of reasoning is relatively fruitless.
I maintain that when it comes to claims that can’t be falsified, it’s best to keep a neutral stance, lest you spend an unreasonable amount of time trying to explain why, just because something can’t be proven false does not automatically make it true.