There is a finite number of hours in a day and a finite number of possibilities to combine different activities during these hours. Even with best of intentions and very decent techniques, it's impossible to have a XOR life with too many things at once without getting exhausted and burned out and getting a temporarily NOT life as a result.
We tend to invest too much time into activities when we limit ourselves. You can work out, bone up your knowledge, eat healthy, work efficiently, and have time for recreation and a family. It take investing time into planning, which feels wasteful when you're overwhelmed. And it might mean you timebox certain activities to limit burning the ocean.
In this context: forcing a choice in activities between one option or other when both are meaningful to a person. That's not to say you should never abandon activities, only that folks tend to over-do it.
