I developed a fear of the smell of pool water when my parents sent me off to swimming lessons.

Started off fine when everyone had extra floats strapped to them. After a few lessons we were supposed to take them off. So one coach started going through the kids, taking off one and immediately moving on to the next kid. I sank like a rock as soon as it's taken off me. Flailed my arms around, struggled, no one came to help. A bit later I saw a glimpse of light from under the water, reached for it, turns out it's the edge of the pool. Pulled myself up, looked around, everyone's doing their own thing, nobody noticed.

Spent the rest of the lesson hiding in the locker room, never managed to learn swimming. My legs still tremble when I smell chlorine all those years later. Like when walking into a freshly cleaned bathroom.