There are lots of people who call themselves
nonconformists. In fact, if we took a
scientific poll, it's probably pretty good odds that the self-proclaimed nonconformists would outnumber those claiming to
go with the crowd. Few people want to be thought of as
running with the pack. So they
dye their hair unnatural colors, or stand it on end, or get piercings in just about any place imaginable (and a few that aren't), or take up
narcotics, or grow
long hair (if they're men) or
short hair (if they're women), or crank up
Marilyn Manson or
MxPx and thusly proclaim
rebellion against the world.
Then, too, this applies even to the things that most significantly define who a person is. Some people will call themselves gay or bi because everyone else is straight. Some people will start reading Marx and Lenin for no better reason than that they see capitalism everywhere. Some people proclaim themselves Buddhists or Wiccans or atheists just because Christians surround them.
These people are not nonconformists. They are simply conforming in a different way. Mainstream society still affects them, it just does so in an opposite manner; they get to the intersection, and instead of going straight ahead they do a complete U-turn.
True nonconformism is not reacting to the mainstream, but ignoring it. It is a person doing what they wish regardless of what the rest of society thinks of it. A man in a business suit and another wearing a shirt knitted from Goodwill rejects are both equally nonconformist, if they wear those things because they want to rather than because of social acceptance (or in the case of the latter, shock value). A true nonconformist can unabashedly listen to Mariah Carey one moment and Rage Against The Machine the next, and the Brandenburg Concertos after that, for no other reason than that they like all three. A true nonconformist does a thing (or believes a thing), not because it is mainstream, nor because it is not, but because that is simply what he wants to do (or simply what seems correct to him).
Mind you, whether any such person actually exists, I can't say. It may simply be an ideal, reached at by asymptote, never fully realized.
Note: Before anyone starts downvoting me (or any gods or Content Editors decided to nuke it) because this topic has been talked about before (in various nodes with unwieldy titles), I should point out that all of these simply poke fun at people who call themselves nonconformists; whereas I'm putting forth an idea of legitimate nonconformism. If you dislike that idea, fine, you're well within your rights there; but please don't downvote or /msg me on the premise that this has been done before.