So I'm fairly sure we all have something weird that we find fascinating that other people would consider gross or weird.
For me it's the body - things like dead skin flakes, snot, scab peelings, blood, hair etc - if it came from my own body I'm so intrigued by it and lose minutes just looking at it from different angles. If I had a microscope I dare say I'd use that and run all sorts of tests.
On the flipside though, that trout from someone elses body I'd happilly be a country mile away from and squirm at the sight of it...