I'm quite an amateur naming enthusiast, by which I mean I find names and the concept of naming things to be endlessly interesting. People's proper names are interesting because there's all sorts of history and genealogy buried in them, even if the people who gave the names (usually the parents) were unaware of it. My own name, for example, tells you fuck all about me (which is an important point that I'll get back to, so keep it in mind), but it does say a lot about the context I was born into. My first name, Christopher, and my middle name, David, belie my religious heritage: Plainly christian, with a West European twist. Christopher, "bearer of christ," is about as explicitly christian as you can get, and David, "beloved," is a major jewish name that christians also like quite a lot. Of course, that doesn't tell you an awful lot about me, since Western European christian influence covers an awful lot of the world.
My surname, Sham, on the other hand, is much more interesting, I think, because it's a bit rarer. To the best of my knowledge, my lot of Shams got their name from Lebanon, where it's Arabic for "North." So I could be reasonably re-named Messiahcarrier Beloved Left. Left? Yes, left, because left and North are the same thing in Arabic. And there's a pretty good logical reason for it. Imagine you're a sailor in the Mediterranean or you're crossing the Arabian desert, or somewhere else that offers few landmarks. The absolute minimum navigation aid you can rely on is the Sun rising in the East (and setting in the West, but presumably you do most of your travelling by day, so the rising Sun comes first). So East is your primary direction of reference, West its backup. Next least complicated thing after that? Stick your arms out perpendicular to your East-facing face and you get two more cardinal points: Left hand is North, right hand is South (which, incidentally, is Yemen, i.e. same as the country at the southern end of the Arabian peninsula). Makes some sense; can you explain why English calls those four points North, South, East and West? Or why we normally give North primacy over the others?
The Shams are apparently the most numerous Lebanese family in South Africa, which isn't too surprising, considering my ancestors got here before most other Lebs, back in 1890-something, having tried out Bermuda and Australia along the way in their escape from Ottoman persecution, and then bred like catholics. But I'll save the full genealogy lesson for another day (by which I mean night, because I can't be bothered to wake up before noon). There are also unrelated (except in the sense of all being of the same species) Shams from India, China and I think Malaysia. Quite a few of these live in the US now too. So there are actually plenty of Chris Shams in the world (including all the Christines, Christians, Chrisanthumums, etc.), and quite a few Christopher Shams just in Joburg alone (relatives I've never met, I don't think).
So being Chris Sham doesn't really tell you much about me. Not only is it not a unique descriptor (unlike my ID number), but the information it does give you (fascinating though that may be) is only about my ancestors' lives, not mine. When I finally get my PhD, I can stick Dr in front of my name, and that'll be the first thing actually about me, achieved by me myself, that my name will include.
Nicknames, on the other hand, are more personal. There are thousands of formal nicknaming traditions, but mostly they're just coincidentally convenient descriptors. In some cases, they're practically compulsory, like fighter pilot call signs, but even that tradition varies from service to service. In the South African Air Force I've seen pilots both picking their own and having them applied by others, while in the US Air Force there's a fairly firm policy that you never pick your own call sign, and anyone who tries to is likely to get saddled with an especially ridiculous one instead. Obviously formal organisations are more likely to have formal rules, but the same general patterns govern all nicknames, it seems. In any society (that I've seen so far), sometimes you'll be allowed to pick your own, but if it's too over the top or silly, then nobody's going to use it, and it may be twisted into something nasty to use against you. More often, though, other people just assign you nicknames. Sometimes they fit really well, sometimes they don't but they still stick.
I have two nicknames that I willingly use, neither chosen by me. My first, Sham, is my surname, used by teachers in lieu of Christopher as a way to tell apart the various Christophers in class (there were usually 2 or 3 of us). For a while that was mutated into Shamwich, Shampaign, Sham&Tomato, plus endless other consumables, but in the end only Sham outlasted high school. My second, Spatula, is a reference to a weird habit I had throughout high school of digging through cutlery drawers when visiting friends' homes. I know I usually went for the biggest knives and the mallety things (unless there was something really unusual and complicated in there to play with), so I'm not exactly sure how we settled on Spatula, but whenever we LANed after that, that's the name that was typed in for me, until I'd learned to do it myself, at which point I just carried on with Spatula because I hadn't any better ideas. And now all my friends (at least, those connected to me via high school friends) call me Sham, while all my online gamey type stuff is done as Spatula.
I've had other nicknames that I've rejected; as far as I know, they've fallen into disuse, but who knows what people call me behind my back (in front of my back, it's usually something equivalent to "big meanie" or "sexy beast"). At the start of high school, there was some older kid who somehow decided that my nickname was "Druggy" and kept that up for at least a few years; funnily enough, I think that guy went on to become a chemical engineer. Then when I was teaching, the kids referred to me (among the names I'm aware of) as Jesus (because I had a beard), Newton (because I taught science) and Mlungu (because I was the whitest thing within 20km). They also called me Mr Sham, which freaks me out; it's a cliche, but that's my dad's name!
All of this is a very convoluted way of arguing against Google+'s "serious, consistent names only" policy. I'm happy to give my full legal name, as well as the grown-up, serious name I put on job applications (the shorter Chris), but those are not very good labels for me. Parents give their children "nice" names in the same way that people try to choose good nicknames for themselves, and the rest of the world is going to react to them in much the same way: Accept them if they aren't too wank, ignore them and replace them with something clearer/easier if they are, or take the piss out of them if they're really too preposterous. However it plays out, human names are surprisingly similar to cat names: Almost never the same at birth as at death. Google+'s policy of setting names in stone is exactly counter to normal human behaviour. And perhaps giving people the freedom to replace their parents' choice of name with their own (the way the rest of the onlineyverse does it) is still folly, but at least you can claim a new name as your own, should you feel so inclined.
Now add in the much more serious fact that there are plenty of very good reasons to want to post on Google+ under a pseudonym, especially for those who face persecution or legal restrictions. Heaps of good examples exist. Google+'s policy still permits all sorts of nefarious fraud, with people pretending to be other people, and just screws over those with delicate RL identities and craps on the self-expression and social realities of everyone else. I am not my name, I shouldn't be chained to it against my will. Google don't really seem to understand what names are for.
(You'll note that, for a post all about how keen I am on names, I've only covered my own names so far. That's because this is a very wide field, especially once you stop limiting it to humans, and I think I'll rather explore it slowly over time, rather than trying to cram in everything all at once today.)