Define obvious. At least the pointer pointer version is obvious to me in this task.
Pointer pointer can't be applied everywhere. If you try to reverse a linked list in O(n) time with O(1) space using a pointer pointer, the code would be less obvious than using a prev pointer.
> but in the end environment friendly means: using less energy (in any form).
Is it? I thought it meant no harm to the environment. If the charging station is powered by solar energy, I don't see how using the otherwise wasted energy wrong.
I like the "house of cards" metaphor. After learning how these three companies could help each other in his biography, I think the possibility of collapse is actually pretty low.
They've already done a good job explaining the system, so I won't do it here.
I used it when I was still in graduate school writing a paper. I managed to track tons of tiny details in the writing process.
I think the most useful thing is the task migration. You must migrate unfinished tasks from today's log to next day's log, manually. During the migration, I sometimes cross out some random thoughts that I put as tasks.
This is the time that you _must_ spend everyday. It somehow can keep up your sensation of completeness. I know some apps can help you do this automatically, like todoist, but I don't think that really works for a long run (at least not for me). I find that if I didn't do the review (migration), I intended to get slow start the next day, and gradually the system would collapse. That's how I failed todoist :(