Hmm… a lot of the stuff they remember probably isn’t real. They said that themself. A lot of people experience memories becoming muddled together, or just remember vividly imagined stories that they heard, and aren’t able to tell those apart from very old recollections.
We have pretty good records going back to the war of the Usumgal, and much spottier stuff before that. Libraries and cities were burned, or just left to be consumed by nature. It’s crazy how fast something will just get overgrown and rot apart and be ruined if you don’t constantly maintain it, and that goes double for paper records.
The pulley gondolas are something that we have no records of at all, but multiple people remember them. It’s pretty well accepted that there was at least one city that had those (although debate about which/where it was), just from how many people have similar recollections of it.
As for magic? I mean we all see strange stuff now and then, and it’s not like I don’t believe in anything, but back then, people probably just called everything magic. They didn’t understand how anything worked, or science or math. I feel like sometimes I believe that stuff was true, but then I remember how many bunches of educated people know it isn’t.