What perfectly normal thing can't you be around anymore due to something you experienced?
Mine is a pretty tame example: I never minded the smell of garlic was fine around it... but I took a job for DHL and they had these large tubs of garlic for horses that had to go out to people. There were about 10 of them coming down the belt.
Now I can't stand it. I'm just reminded of how strong that smell was I was actually gagging.
The tubs were heavy, the handles were feedble. Some of the tubs were damaged so I got a bit on me.
I stunk of it for the rest of the shift. It wasn't even a normal garlic smell it was just so powerful and nauseating.
For me, anything "bubblegum" flavoured or smelling. When I was a teen, I had to have 4 teeth taken out, but it was done in 2 sessions so I didn't have my entire mouth out of action (it was my back teeth on both sides, top and bottom), and both times the mouthwash, and the numbing gel they used before the injected one was bubblegum flavoured, and I can't stand it anymore because of dealing with my teeth being pulled out my face