That can´t be it. By that statement if I belive that I can fly that would not be the "Truth". Therefore the "Truth" has to be a CONSTANT.
Can you believe your own senses? A car air freshener tells your nose that theres freshly cut summer hay around, but there isn't. You watch a tv and see Sandra Bullock floating in space. That’s a lie, it was movie magic. Maybe you know that, maybe you don’t. You’re not even seeing her, you’re seeing some flashing lights which convert to electrical signals your brain interprets as being true. Can you trust those signals? People hallucinate all the time. The truth is they can hear voices, even though nobody else can, because of misfiring neurons.
You can probably have mathematical truth - at least as far as your universe appears to work. That truth can be tested and refined, but for day to day truth things are more nuanced.
1st what is to fly? You've already made assumptions i.e. beliefs elsewhere.
You can definitely fly. Try it on a cliff. You might die. You might not go very far. But you can.
The earth has always been earth-shaped. We can think it’s flat, spherical, “turnip-shaped”[1] but the universe doesn’t care what we think. The earth doesn’t change shape based on our perception.
[1] Yes some people think this for some reason I can’t fathom
And you never needed more than 640KB of RAM [1] right? Your "statement" is based on your knowledge today. You'd be burned for witchcraft back in the days for saying the earth was not flat.
> but the universe doesn’t care what we think
Assuming you know what the universe is. Your theory is based on your limited today knowledge. Someone sometime in the future could say something completely different (just like you talking about those of the past).
[1] famously from 1981