I could chalk up what I'm about to describe to you as me simply being an "evening person", but I'm interested in whether the following is a well known phenomenon, very common, and or simply trivial and unimportant. A bit of background info: I am between the ages of 15 and 20. I love math. I love doing nuanced math problems, I love reading about math, learning math etc. Whether it is modern algebra, analysis, topology, geometry, number theory etc. is usually irrelevant (there are a few exceptions i.e. point set topology w/o any motivation). I only started liking math around a year and a half ago (I was originally interested in physics, but I eventually got a lot more interested in mathematics). Before that I really didn't like math. I distinctly remember that I didn't even understand things like the formula to compute the slope of a line using two points on it. In the morning I almost always feel somewhat groggy and slow. I feel like I think slowly, think more shallowly, am able to process information less effectively, and cannot work things out all that well. I can barely feel my pulse (as measured at the side of my head). However, in the afternoon (past 4 pm), especially while doing mathematics, I not only feel as though I am able to think much more effectively, I also feel a surge of motivation, and can work for hours on end without noticing the time go by. Math in the afternoon seems to induce a good feeling overall, almost like a drug. In addition, the pulse in the side of my head also feels much stronger. This same feeling can be induced by chewing gum, to a certain extent. The phenomenon described above started just a little bit after I started to really like math. Before that I have no recollection of anything like this ever happening. I acknowledge that it is wholly possible that there is no connection at all between the two events (starting to like math and the various physical and mental symptoms I described). However, I would like this forum's input! Has anyone had experience with similar occurrences? Is it all in my head? I am truly curious.