Now that the manga's over, what were your early misconceptions about JJK?

I discovered JJK through a science magazine in my country that sometimes includes a booklet with the first chapter of a recent manga. I read it but I remember not being very convinced and I didn't give it another try until the anime came out a year later, which was when I started thinking it had a lot of potential.

I wish I had tried getting into it sooner to see all the theories that people had when JJK first started. So it's a bit late to ask but what were your early theories for those who were there since day one? (or those who managed to avoid the disgusting amount of spoilers)

Personally, I thought Domain Expansion wasn't that rare of a skill at first, and that the main trio would all have it by the last arc. Instead Yuji only used it once, Megumi never completed it and Nobara isn't anywhere near close to having one.

I also thought that Gojo's technique included a bunch of other colors like lime green or yellow.

And I expected to see way more students than what we got. Even if we include the Kyoto school, all the students we've seen are barely enough to fill a single classroom. I would've liked to see the school setting used a bit more often to really bring the point home that they're just a bunch of kids who shouldn't have to go through so much trauma.