Upside down

There is a map of the world in my friend's office. The map, however, is a little bit different from the normal ones we've seen so far.
How?
Well, actually it is designed upside down. I mean, the northern hemisphere has gone to the south and vice versa. So we have north pole in southern hemisphere. All of the countries (or better to say, every thing) below the equator are those miserable ones which have been in the northern part previously.

This, although funny, reminds us that many of the current rules and regulations, problems and properties,... are results of such sort of conventions. I'm sure that none of us has asked his/her teacher about this. Why we are in north and they are in south? Why those below the equator (except a few of them) are thought to be lower in many aspects (compared to the residents of the northern part)?

Remember, no matter what the maps say or what the divisions are, you can be the heart of the world...