It seems absolutely ridiculous to assert you're the only one on Earth that can talk with authority about "a correlation between music and watchmaking." You don't need to be a highly successful musician turned master watchmaker to talk intelligently about that. There are surely many other people that know a lot about both music and watchmaking. For example, just me, n size 1, I have a friend who formally studied music and collects high end watches as a hobby and has built his own geared watch. I'm sure he could comment intelligently on this question. Not really understanding the downvotes here.
It didn't seem like he was saying "yeah I guess I do have a really rare perspective", it seemed like he was literally saying "I'm the only one." Maybe he's even the best person in the world to ask, if you could only ask one person. But the only one? Maybe his comment was playful/less literal, but it didn't come off that way to me.
Seems like an obvious comment to make about being rare as hen’s teeth.