Here’s my take on this, and this is my personal opinion as a player who played launch week in the US and then restarted on EU when the servers came up here, but also as someone who’s been here at Blizzard for the past 11 years.

Classic is kind of like dusting off that old NES and firing up Super Mario Bros again. It’s ingrained into you, you know the maps, the worlds, you can remember things, it doesn’t mean you’re going to one clear speed run it though.

Even the most old school players from Vanilla can make mistakes, and that’s totally normal for something as massive and complex as WoW is.
My own playtime in Classic would be described as sub optimal, but I’m not there to be BiS everything, I’m there to re-explore a world I fell in love with and still hold very dear.

Sure now a days the resources available are far improved, having info at your fingertips online is a massive help. Meant I didn’t have to dig out my old Brady Games inch thick companion book and world maps again and my folder of notes
I still did, and my original WoW mousemat from back in the day just to have them nearby, hoping some of that old lore and knowledge rubbed off again I guess.

No one should be expected to know everything, you can’t, there’s simply too much out there in Azeroth to even try.