I went to the hospital and got some medicine because I was having some trouble sleeping lately.

Now I have two kinds of sleep inducing drugs at hand. For some reason, both of them say in my medication book that they help me fall asleep more easily. What is the difference?

I think I wrote this article last year. For a while I was looking for something like "sleep quality," which I doubt if there really is such a thing. I tried various things, such as room temperature, humidity, when to take a bath, and so on.

However, talking to friends around me, colleagues and students at work, it seems that I often have trouble sleeping much during the rainy season and summer months.

People half my age said the same. People twice my age said the same. So I guess my inability to sleep is more like the ground shaking than me being pinched.

From January 1 to December 31,

I've learned that if my sleep times were stable like this, it would be rather unnatural.

Perhaps, like "sleep quality," "mental stability" would be rather strange if it were like a horizontal graph.

It is not horizontal. It is not like an uphill slope. Maybe if it were like a stock price, that would actually be just fine.