I understand why people don't worry about things.

For everything in life, there's a limit on exactly how much preparation you can have for things. You a limited amount of time to study for a test. You have a limited amount of time to prepare for an interview. What you do in that time will be reflected in due time - so what's the point in stressing out over it?

Granted, not all stress is bad and stress can be used to push you to do your best, but then there's the unnecessary stress. People freak out so much over tests - before and after them. You know what you know, and you know what you don't know. Now, it's time to put it on paper. You can study to do better, but you also have the choice not to. Doing anything else than that is just pointless. Losing the sleep thinking about the next day's test isn't going to help. Shaking from the questions on the test isn't going to help. Freaking out over the results of a test before you get them isn't going to help. Why worry?

Go to sleep knowing that you did all you could have done. Write the answers down as best as you can. Sit back and relax until you get the results. There's no reason that you should be losing sleep or panicking over anything, because it's either going to make things worse or do nothing.

Sometimes I catch myself getting anxious over something and I have to fix that, but I look around and see people that act like their whole life is a minor misstep away from crashing and burning. They always panic, they're never happy - or anything but terrified. Meanwhile, I'm over here doing a nose dive, but at least I'm still keeping my cool.