I'd recommend you go ahead and legally change it. It's not an involved process in California. The problem with just calling yourself by whatever name you want to use is it can bite you at inopportune times. Specifically my friend who has been "Chip" all his life but legally Alexander ran into problems with the heightened post-911 security when sometimes his tickets ended up matching his credit cards and not what was on his passport/driver's license.
When you do get your name changed, get a bunch of extra "certified true" copies of the order. You'll need to show them (and sometimes hand over) these to people to get your official stuff changed.

