An interesting informational graphic: All of Inflation's Little Parts, from Saturday's New York Times. This is a graphic that breaks up the many parts of the standard "basket" that is used by the US government to compute the inflation rate.
Of course, nobody is exactly average. To take an example dear to my heart, 0.1% of this basket is "books". But how many people do you think spend exactly that portion of their income on books? My instinct is that the distribution of "percentage of income spent on books" (and a lot of the other small items) has a long right tail. Plenty of people I know (who are of course not a uniform sample) spend, say, two or three percent of their income or more on books -- and it's my understanding that the book industry relies quite a bit on people like us.
Somewhat more seriously, 23.9% of the basket is "owner's equivalent rent" (what homeowners would pay if they were renting their homes) and 5.8% is actual rent. That means that a typical household making, say, $50,000 a year spends about $1,000 monthly on the house they own (or would, if we weren't having a housing bubble), and $250 monthly on rent. But it's very hard to imagine a household that actually does that! The mean and the mode, in distributions like this, are very different. It would be quite surprising, I think, to find someone whose spending breaks down exactly as in the graphic.