Nightmares are those terrible dreams that haunt our sleep. Some people get them occasionally; a few get them constantly. The psychiatric profession uses them to treat other problems. For most of us, though, the question is: what constitutes a bad dream?
There are the obvious dreams where one is being chased by some fiend, known or not, and feel the mortal terror of being caught. The other extreme has us frozen in a situation where we are powerless to move or to change that which goes on around us. Even with the trousers at home for the big calculus test and the hot breath of the beast steaming against the back of our necks, these are still fairly tame.
What bothers me more is the pleasant dream. Monsters run from me, and I haven't enough shame to worry about the location of my trousers in a long time. The pleasant dream is insidious though. It doesn't attack you in your sleep, it waits until you are awake to do its harm and then it has you for the remainder of the day.
How can it do such a thing? Easy, it shows you the path you didn't take and all the things that could have happened if you made the other decision. It doesn't matter that there is no proof that the other choice would have worked out as shown in the dream, it still takes you to lofty spaces. Then the alarm clock sounds and dashes you against the very real opportunity costs of the choices you made. In the grey light of dawn, knowing that you chose strawberry ice cream over glory rips the bones from your soul to leave you a gelatinous mess.
When the creatures come in your next nightmare, you can take comfort in the fact that they are at least coming at you in honest fashion. They aren't setting you up to fall on the sword of your own folly. You can fight the monsters and, at most, they keep you from a restful sleep. They don't dig their long, cold fingers into your day.