I was invited by the professor to work with him. His area is outside of my background and I agreed because I was curious and haven't found a research area yet. After beginning to read papers and learn more, I find I'm less and less interested in the topic. I feel torn as to whether I should continue, and if I shouldn't, how to gracefully exit.
On the one hand, I feel I should develop professional relationships and skills. The topic is a valuable thing to know about. It would be almost wasteful not to take this professor up on their offered mentorship, and rude to stop now. On the other hand, I find other courses much more compelling. I can't really see myself working in this area for PhD work, so it might be a waste of both of our time to continue.
How can I decide whether or not to continue, and if not, how to politely end the relationship without making the professor feel that I've wasted their time?