My Professor's Pet Project Became Mine Too

Hey there! So I've been working with this professor on a research project for almost six months now. It started out great; we were supposed to be researching new methods in data analytics, but then he got really excited about some niche software that was only tangentially related to our main project. I tried my best at first, trying to keep up with all his wild theories and late-night emails about the software. But honestly, I found myself daydreaming about my thesis work more often than not. One night, I accidentally installed this software on his computer while setting up some files for our main project, it was supposed to be a quick fix for something unrelated. Well, he came back the next morning and was thrilled with how everything worked out. Now every time we meet, half of our discussion is about tweaking that little piece of software that I basically introduced by accident. I feel bad about it because I know deep down it's not really adding much to his actual research work, but here I am contributing zero on my end and just nodding along as he talks endlessly about this software he loves so much. Am I a terrible grad student for letting him be happy about something that isn't even part of our main goal?