I wouldn't call it a "philosophy." It's a suggestion based on my direct experience. I've tried calendaring as a way of prioritizing and for the reasons I've explained above it didn't work for me. In fact I found it to be counter-productive. I'd be willing to bet that people like @Longstreet who use time-blocking to stay focused had to first make an internal commitment to prioritize certain things in their life. Only with such a commitment in place can an external tool be useful in staying on track. Excessive fear -- like the fear of saying "no" -- is the product of distorted thinking. It's the unfounded worry that something catastrophic will happen if you do the thing that you fear, even though there's nothing but evidence to the contrary. Again I'm telling you from direct experience that simply blocking out time on your calendar isn't enough to overcome that fear. First, you have to overcome the fear by countering that distorted thinking with more accurate thinking. Then you make different decisions based on that more reasonable thinking. At that point you can use external tools to help you implement your new decisions. Not the other way around. At least not in my experience. And yes, I remember the discussion about the piano player. At that time you were against time-blocking. I suggested that scheduling rehearsal time was a perfectly good use of the calendar because it's time-sensitive. If you don't practice enough for the recital, you won't be ready. But again without the internal commitment to practice the calendar won't help because you'll know you can blow it off if you want to.