Gradually Recovering From Minimum

Since the end of the vacation, the derivative of my talent on academic has been a negative value.

A most apparent evidence among the observables is my speed of reading academic literatures of high difficulty. Before the vacation, I can read 10 hours of "Lecher's Nine Volumns" without much pressure. Now, however, I found it's just impossible of concentrate on it for a considerable period. When I read An Introduction of Solid State Physics, I'm just exhillarating. But now, I fall asleep each time when I read it.

The negative derivative dues to the value of several variables.
The predominant one is emotion. Though I was fairly happy during the vacation except for a couple of irritating events, I came across several quarrels these days. I found I show no fear of breaking friendship when quarrelling, but I regret and fear of the loss after them. I must make some adjustment.

However, it's becoming positive again as I adjusted the value of those variables.