Guru. Ninja. Rockstar. Expert. These descriptions are all over the place. (*cough* Twitter bios *cough cough*)
Done learning. This is what I hear.
Here’s the deal. Calling yourself an expert sounds like you think you’ve got nothing left to learn. How can you be an expert in web analytics, or social media? These fields have been around for all of about forty-five seconds. (And they’ve changed twenty-seven times since then!)
My $0.015: Don’t ever call yourself an expert, a guru, a rockstar. (And don’t just replace it with samurai or swami. You get my point.) Someone else may call you that, but let’s be honest, even then you should shrug it off.
The most appealing trait is a desire to learn, improve, to continue honing your skills. Focus on that. Let your work and development prove yourself. Not a self-appointed noun.