Or, how to have fewer colds.
This is expanding on an incident I mentioned in Chatterbox, which I was reminded to do by an writeup by mokey, from whom the first two sentences below are stolen:
"I used to get sick quite often. I would come down with a bad cold maybe 5 or 6 times a year."
This was true for me, too.
Unlike mokey, I now have a clear understanding of why I used to get sick.
I lived with people who had long hair, and once in a while I would use my fingers to clean out the drain before taking a shower. This meant picking up the accumulated hair and transferring it to the nearby trash can.
Then I would happily take my shower, water splashing everywhere. La la la.
Once when I was sick with a cold, it struck me that I had recently cleaned out the drain in this way in the few days prior. I didn't think much about it at that moment, but it flitted past my awareness briefly.
A couple months later, I had another cold. And then I realized: Oh! I had just cleaned the drain a couple days before! The connection was made. It seems so obvious in retrospect, but at the time it was a major life revelation.
A few months after that, I cleaned the drain again, unthinkingly, just lapsing into an old habit, and then started a shower. A minute in, I realized what I had done... and knew that this time, if a cold came, that would cement the theory.
Sure enough, a day later, I felt the cold coming on, and it was another bad one.
From then on, I changed my ways. No more cleaning the drain with bare hands before taking a shower.