I ask because it’s considered common knowledge that you can’t but I regularly have dreams where I continue books I’m reading irl (they usually devolve into naritive nonsense over time and then sometimes to blank pages, but the actual text is definitely deciferable), text messages, computer screens, and road signs, in both lucid and regular dreams. Am I the odd man out or is it actually just something people say?
I remember, watching an episode of Batman, the cartoon. In that episode, Batman was trying to figure out if he was in the dream or not, and he open books to see if he could read and realize that there were no letters in any of them. And that’s how he could tell he was dreaming because you can’t read in a dream.  from that day, I’ve always tried to read in my dreams, and so far, as far as I remember, I never succeeded. 
This is exactly my experience as well. Same inciting incident.
If you want to try to learn how to know you’re dreaming while in a dream, you can check out !luciddreaming@lemmy.world. I’d mainly suggest you check out r/luciddreaming for learning to lucid dream (has loads of info for learning + has been around for over a decade and has a bigger userbase). Beware of YouTube videos though, as they spread misinformation. I’ve lucid dreamt a handful of times and it’s pretty fun!