In Windows XP sometimes the screen gets turned in the wrong direction. So you are looking at it sideways or upside down. The easiest way to deal with this problem is to physically turn the monitor on to its side or upside down and then it will be the correct orientation. Another way of doing it is by clicking ctrl+Alt+up arrow. The orientation was most probably changed that way to begin with (clicking ctrl+alt+other arrow).
Sometimes life is like that too. You do something small and find that suddenly your orientation is way off. The easiest way of dealing with it is to adapt to your new orientation, such as turning your monitor upside down. The more correct way of correcting it is to figure out how to get your orientation back the way you want it to be and hopefully on the way figure out how it got screwed up.
In the JPost today there was a story about a teenager (17 year old) who was convicted of killing his mother and wounding his father because they took away his video game. The judge said that he firmly believed that the boy did not realize that by killing his parents they would be gone forever, however he denied an insanity plea and said the boy was responsible for his actions. Talk about needing a reorientation.
UPDATE: I just realized that while this story was in the jpost, it did not happen in Israel.