it's confusing when I try to look up info and every blog post written by a trans person has a story where they always kinda knew.

I wouldn't worry much about it. People who have already transitioned have the benefit of hindsight, and you haven't and don't. Once you're on the other side it's a lot easier to look at prior experiences through a new lens.

And everybody experiences sex and gender differently, anyways. My son loved wearing princess dresses when he was very young. And those stupid Hulk Hands gloves. He definitely didn't KNOW then.

I didn't consider I might not be cis until my late-20s personally. I only realized after I started questioning that I had signs and was totally oblivious to them before. I think some people legitimately know early. But I think there's pressure to conform to that narrative when making cis-facing media because it seems to make a stronger case to cis people that its something innate and unchangeable.

For me, one of the big reasons I never seriously consider I might not be cis is because when I first learned being trans was an option (late high school, and I didn't understand what transitioning entailed at all), I just assumed I was cis since I didn't always know I wasn't (even though I didn't even know that was an option).

Some people retroactively reframe their experience after realizing it.

I strongly do not resonate with the narrative of "always knew since you were 3" but that doesn't make me less trans per se, even if I might not experience dysphoria as acutely as said person