I linked to other posts in that post, in which you can see some of the things I struggled with (written while I was struggling). For example:

1. Windows opening and closing seemingly at random when using SLIME 2. Horrible default fonts 3. Unfamiliar keybindings, some of which are awfully long keystrokes to do very common actions, e.g. C-x C-f to visit a file, C-x C-s to save a file. 4. Struggling with Emacs jargon and navigating the help system

There was a lot more. Part of the problem is that none of these things bother me any more, because I've drilled them into my brain over the past two years. So I don't remember everything I struggled with. I just remember being extremely frustrated.

For the most part I never found solutions other than getting used to the Emacs way of doing things, and changing my habits.