After reading the Havamal, I found that verse 23 particularly interested me. It says:
A foolish man
is all night awake,
pondering over everything;
he then grows tired;
and when morning comes,
all is lament as before.
This essentially means: Foolish people stay up all night worrying about things, and then by the time of morning, they are really tired, so they continue being gloomy and mournful. This verse is pretty much advising that mourning, especially if it is obsessive, over the top, and unnecessary, is bad for you.
The modern world is a very fast paced world. Anybody who blinks often gets left behind. This could be why depression rates have shown a steady increase over time. (It could also just be that we diagnose it more frequently because that particular branch of science is expanding rapidly.) So, especially in high school, where a lot of people seem to be stressed and weary of the work that is needed to succeed, there seems to be a lot of worriers, myself included. This then serves as a helpful reminder that worrying is not always helpful, and can lead to a vicious cycle that causes more worrying, which in turn causes less success, which in turn causes more worrying.
Since we have recently read Shakespeare and we are going to read more, an example of this verse’s application to Shakespeare seems most fitting. In Macbeth, Macbeth is constantly worried about whether his evil plans will work out in making him king. However it is this worrying, especially about the prophecy of the witches, that hinders him from making any logical decisions. He clearly must know that Macduff or some other noblemen know he is guilty and so even if he succeeds militarily in putting away his foes, his kingship will never be legitimate and accepted by the people. But it his worrying (and his pride), that cloud his thought and rather than pushing him towards giving himself in, make him lust for more power, eventually causing his downfall.