To be accurate, I should have been using the word "fixation" rather than "obsession."

I've never actually had foot fungus. I just know that you can pick it up in communal showers and I didn't have any protective footwear.

I was aware of, and being really careful about, not acquiring any of the really nasty stuff you can pick up in hospitals, but I had a long successful history of protecting myself from all those bugs at work. I guess that's why I wasn't fixed on any of that. I'm lucky. That would have been bad.