Xah Lee has an interesting post of the frequency of Emacs functions in the Emacs code base. It’s easy to write such a thing off with a shrug but I found the chart fascinating. The first five most frequently used functions are setq, if, defun, let, and and. That’s not too surprising, of course, but I would have expected car and cdr to be in the first five.
As Lee says, it’s an interesting exercise to read down the list and find the first command you don’t already know. In my case that was oref, which is an eieio function. My excuse for not knowing it is that I’ve never used eieio. More to the point, though, is that now I do know it so I’ve learned something new.
Take a look at the list and see how far you get. Like me, you’ll probably know almost all of them but there may be a few that are new and then you’ll have learned something.
UPDATE: Fixed link.