Why does everyone have secret nickname?

[eftertanke]

I changed my alias because I had been a dick to a bunch of people. Simple as that. It eventually got out, but by that time I'd grown the grapes I needed to admit the mistakes I'd made and keep on rolling.

I use a different name in-game. But that's so that people don't know who I am if I'm on my server. It makes life a little more pleasant for everyone.