I still read Mastering Emacs from time to time. Recently, I was just checking
an article on regular expression. I have been using Emacs for about 15 years and
I am afraid that now I would be far more comfortable with most key chords after
two or three years of Spacemacs. This is not that I really like modal editing–I
don't like it at all in fact–but the consistent key bindings conveyed via
which-key and the configuration layers for most packages make it a really
pleasant tool to use on a daily basis. I've come to have only Emacs on my
desktop. No more iTerm2 or Marked2 or even Desktop icons.