I feel like you get me. I rolled a prot paladin as my main the first day of TBC and never looked back (until Classic WoW). Each expac I used to hit the internet and study every dungeon boss before I went in the first time so that I’d know something about what I was up against, but getting to know a new dungeon is still a process. I did have a guild but there wasn’t much left of them still playing by Cata. By the beginning of MoP I just decided not to run instanced content with pugs anymore because I didn’t want to deal with the dice roll of finding out if the group I joined would be willing to practice a little patience while I was learning. I kinda developed a complex that if I didn’t learn every new instance within a week of launch I might as well skip the expac because nobody wanted to wait for me.
Now I have delves and follower dungeons which I think are great. I’ve been running both solo and with a few friends I met in my Classic guild. But I still haven’t come up with the guts to queue for any instanced content with pugs yet. I’m thinking over possibly some normal or heroic dungeons, but even some of my friends won’t go if there’s pugs. Or if they have to queue solo. Apparently some of them have developed the same complex I have, afraid to deal with pugs.