I live my life by the "4 good hours" rule, inspired by the book Deep Work by Cal Newport. If I can put in 4 good hours of deep work where I am iterating and learning on a skill, I consider the day a success.
This rule is specific to improving at a new skill in flow state. This does not mean I blow off the rest of the day or refuse to answer emails after those 4 hours. I still exercise, answer emails, write documentation, cook dinner, etc. It just means I choose to be kind to myself after I've achieved those 4 good hours.
After you work at a job for a while, things can tend to be come stale and you stop learning. I have a novel approach to this: I find a new job that will actually be challenging. This is actually harder than you think!
In Deep Work, Cal estimates that you have 4 good hours of learning in you a day. Hell: You probably have less. The four hour rule refers to virtuoso violin players[0] who I am willing to admit probably have more talent and dedication than my stoner self.
0: https://www.johndcook.com/blog/2013/02/04/four-hours-of-conc...