Things I wish I knew about emacs earlier in life:
Emacs benifit plan volume 1:
* You will finally love the ui/ux for `info` pages
* macros (save and repeat a sequence of commands, commands can be applied to anything)
* registers (save locations in buffers, save text for later pasting)
* Frames (M-x speedbar for starters)
* modes (which to use and how to configure?!)
* built in documentation is awesome!
* what does this sequence of buttons do is only a `Ctr-h k <sequence of buttons>` away
* Mostly solid remote editing (tramp mode is no match for rsync on large files, luckily, RMS and friend have afforded us our freedom and we can configure this to our liking.)
* Freedom (as already identified by many people here but not by the word 'Freedom'. Also Freedom causes longevity. I have no source on this)
* Why is Freedom not number one on my silly list? If this were ORG mode I could bump it up to the top quickly.
* Excellent (multi-language (multi-language)) support. This is a recursive joke and the base case for me at least is English Bash. Emacs is language agnostic and language aware
* You will never have to write a 'throw-away' shell script ever again because emacs macros are that good. Still like shell scripting, incorporate shell commands in your macro.
* Carpel tunnel syndrom (cts) is a real thing, but, IMO, poor posture is more likely to give you health problems than cts. In reality, with Ctrl-R reverse search and Ctrl-S forward search, you can basically cycle through every command you have ever typed.
* Default key bindings in bash are emacs based and I actually enjoy the emacs bindings more than the vi ones despite spending lots of time in vim
Last reason: It's fun to play with a "real time display editor" and realize that emacs is an endless journey on the road to freedom in your ability to manipulate computation, however it may be expressed in years to come.