I had absolutely no interest in pain when i started my rotation. Like you, all it takes is a great mentor and exposure to the good/fun side of pain medicine to realize that it is a great career...
Too often on this board you see posters talking about how much $$$ they make, for the hassle they put in. Ignore them, set up a practice that you like and can feel accomplished, and it is worth it even if you dont make millions...