Most people go through life perfectly happy in the knowledge that the real earth looks like it does on a standard Mercator projection map. Cartographers, map nerds and those that have seen this scene from the West Wing know that this is not really the case.
Wikipedia sums up why map projections are necessary in the first place:
Map projections are necessary for creating maps. All map projections distort the surface in some fashion. Depending on the purpose of the map, some distortions are acceptable and others are not; therefore, different map projections exist in order to preserve some properties of the sphere-like body at the expense of other properties.There is no limit to the number of possible map projections.
The comic above by Randall Munroe at XKCD looks at What your favorite map projections says about you (assuming you have one).
read the full article: http://brilliantmaps.com/xkcd/