Why don't you just snap out of it?

One thing that I find is difficult with the human condition is that we often have little empathy for others. It's not that people should be altruistic toward others it just menas that people fail to understand others mindsets. Have you ever said to somebody "Snap out of it!", because they were complaining or stressing out about something that happened that you didn't think was very significant? Have you ever walked by two people having an angry discussion and thought, why are they so angry it's such a nice day out? Have you ever looked in annoyance at people having a nice day out at a restaurant and laughing when you were feeling miserable?

These are all examples of the contrast of mindsets and moods. The same thing can be seen in people even from day to day. One day they are sad and the next they couldn't understand how they could have felt that way. The truth is is that a lot of people can think they can sway other's moods or change their personality just through words. Prozac might work but words don't do much. Mental states are set in stone only subject to the whims of neurochemistry.