This is probably the first time I've thought of writing a post based on some thoughts I gathered from the comments space of a post on someone else's blog.
Your mind doesn't work the same way, or equally actively, at different points of time during the day. Or at different places. Or during different phases of your life. There are some things you can do better in the afternoon, and some that are better taken care of late in the night. And then there are some which refuse to let you have a moment's peace until you take care of them.
There was a certain lecturer we had in College, who used to tell us that, no matter where we are or what we are doing, our minds should always be looking for a solution to a Mathematical problem or the proof of a theorem. He used to tell us things like, if you are hanging on for dear life from the door of a DTC bus, and the conductor asks you to buy your ticket, you should tell him to wait until you figure out the solution to the metric spaces problem that's been bothering you all day. He narrated this incident when he, after much effort, came up with the solution to such a problem, and began to dance around in his balcony for the benefit of his amused and startled neighbours.
In those days, I was sufficiently enthralled with Mathematics to be able to relate to all this. There were times when I tossed and turned a problem in my head on the bus ride home. Times when I woke up in the middle of the night with a sudden breakthrough. Or, if my brother is to be believed, mumbled things like a(n) tends to l in my sleep.
You know when I get most of my ideas? When I am taking a bath. It's the only time during the day when I shut the door, literally and figuratively, on the rest of the world, do away with my worries, and relax. And only a relaxed mind can figure out that last remaining step in the proof of a theorem. Or the last line that fits into a poem that I've been trying to write. Or the subject for my next post. This is mostly applicable for my evening bath, because mornings are generally a little rushed, given the fact that I need to get to work, and that I certainly don't like making my carpool friend(s) wait. This is the major reason why I do most of my blogging late in the evening. All through school and college, I made it a point not to study beyond eight or so in the evening. But when I was worked up over something interesting, something Mathematical, it would, more often than not, come to me late in the night.
On the other hand, I can hardly, if ever, write code in the later phases of the day. That, by the way, is, supposedly, what I do for a living. Apparently the relaxed mind works very well at what it does, but it does only things that it likes to do. And the tense, tired mind grows relaxed if it does those things.
I've read a number of articles in Reader's Digest and in other places that tell you to figure out when your mind is most active and when it slumps, and organize your day accordingly in order to maximise efficiency. Tasks that don't need your mind to be too active, like sorting your mail, should be taken care of post lunch, when you're feeling a little drowsy. And code should be written whenever your mind is at its wakeful best.
I think this stuff makes a lot of sense, and I try to abide by it as much as I can. But what I find more important than all of this, is that, each day, everyone needs to schedule some time exclusively for an activity that relaxes their mind, makes them happy, and gives them a sense of achievement. If you're one of the lucky souls who get all this from whatever it is that you do for a living, great. Otherwise, you need to mark some time for this in your daily calendar. It works wonders.