Are you a poker pro? Do you know one? I'm not asking if you know Phil Ivey or Howard Lederer. In my opinion, those guys are extremely successful poker professionals, but you really don't have to be that good to go "pro."
In the purest sense of the word, a professional of profession X is someone who makes a living by doing X. Whether X is poker or hockey or sculpting or sales, the definition applies. So if you can get by with a lifestyle that only costs $100 a week, and you make that much a week at the tables, you are a poker pro. If your lifestyle requires you to provide for a family and pay a high-interest mortgage and you make $300 a week at the tables, you are not a poker pro.
A lot of people claim to be semi-pro players. What does that mean? To me it means that you make enough through poker to pay for at least some aspect of your life. Using my college experience as an example, I could pay rent with my winnings, but needed another source of income for food and entertainment.
By thinking of poker professionals from a monetary standpoint rather than an assessment of pure skill it keeps things in perspective. Practice to never assume anyone is better than you before you sit across from them. Skill will show itself in the statistics.