A Bristidh tabloid once had a huge above the fold headline of a shocking educational discovery: "HALF OF ALL BRITISH STUDENTS ARE BELOW AVERAGE!"
Even things that are supposed to be equal form normal (Gausian or bell-curved distributions). Take the simplest form of equality...the flipping of a coin. Either heads or tails. Ask 100 people to flip a coin 100 times each and record how many times it comes up heads, and only 17 of them will get a perfect 50 head/50 tails. Of the remaining 83, half will have more heads than tails, and a histogram would show a bell shaped distribution.