Why Pain Management?

Hello everyone!
I currently work in a small pain management office as a CNA but I also do some medical billing when needed. I started wih the office in July 2009 and began the CNA course in August 2009 (I worked part-time) and was certified as a SRNA (in Kentucky, we're actually State Registered Nurse Assistants) in December 2009.
I've been with the company since, and am currently going to school for my ADN. I've started thinking about any specialty that I may want to explore once I have my degree and license.
I've had the chance to observe a lot of procedures during my time with the office, and I honestly think that I would like to do pain management as a specialty.
So, my question to all of you is this: "How did you choose pain management nursing?"

Thanks