A childhood belief about being ill

At school, my swim teacher told me to run to the changing rooms, dry myself and get changed as quickly as possible or else "a cold might catch me."

I think it was a cross between the myth that being cold or wet makes you catch a cold, plus her desire to make me not dawdle. I was always skeptical but I never outright disbelieved it until later.

She'd describe said "cold" as being a huge, slimy green monster and when it caught you, you'd sneeze once, then fall sick with a cold.

At one point, I sneezed and she jokingly said, "That cold has caught you!". It was actually hayfever, but I freaked out.

She'd sometimes state that she could see the "cold" and I was wondering why I couldn't.

When I told her that I'd never been assaulted by a green monster, she said that the cold must be a very slow runner or I was a very fast runner.

At one point, I was scared because I thought I had slime on me and that "the cold" had caught me, but it turned out to only be a snail.