a PS to what TheLady wrote
For me, an alias is not about hiding, either. I use them to 'create a name for myself' that is specific to the context in which I am using it. It is nice to be able to shrug off some of the things people will associate with my name, in the same way that it is nice to be able to leave my body behind in written or electronic communication. An alias for me is not about false impressions, it is about incomplete impressions that give me a chance for a fresh start.
Of course you can create an alias like 'kitten' or 'skywalker' that associates you with an interest of yours. But I rather use aliases to start with nothing, so others will judge me by what I write or do, not by associations brought along by my name.