I wish someone could write a "The Good Parts" book for Emacs. Even after reading the manual twice, I'm still overwhelmed with the API and forget even the most basic configuration options after a month of inactivity.
I'd like to take this question one step further: When do you think is an appropriate point to take a sabbatical? After working for a year, two years, three etc. The reason I'm asking is that junior developers might feel the need for a break earlier in their careers compared to experienced devs.