Where this system goes wrong is when we take on more than we can handle. Suddenly we look up and that single side project has become four. What used to steal an hour each week from our main source of income now takes three. It happens, and it happens very easily. I try to always view my time and attention like a steering wheel. If I keep both hands on the wheel, I'm in control and focused on my primary goal. When I take a hand off the wheel, I might still have control, but it's a weaker control, a compromised commitment. My focus is divided and my success is no longer guaranteed.
Work functions the same way for me. When my complete time and attention is bent toward my job, things go well. When I borrow bits of that time to spend on side projects, it is like taking one hand off the wheel. I can manage it for a while, but over time everything suffers. Income drops, quality withers and standards drift.
Keep both hands on the wheel as often as you can. And when you send trouble in your core role, scale everything back and focus on the essentials for a while. You'll right the ship and stay the course.