Here's what I think: There are some things that I know are true, and they are true. There are some things that I think are true, but I am mistaken, and they are false.
I think the same is true for you, reader. Although maybe the things we know that are true are different, and the things we mistakenly believe are true are also different. And the things we agree on? Who knows.
So here's the problem: How do we know which of the things we believe to be true, are true, and which are not? Now that's a thinker. Some people might be better at recognising truth and falsity when they come across it than others, but no one is perfect at it. Or at least, none of us regular, non-divine, ordinary humans are.
But that's not the real twist. Here's the twist: Is what I just wrote in this blog true, or not true? Right now, I certainly believe it to be true.
Do you get it? I'm eating my own tail!