Well, it’s not so much in the cooking as the tasting…
I have a friend who used to own his own bakery. I was helping out a couple-three days a week, getting paid under the table, just to make it easier on his busy days. I’d done a fair amount of baking on my own, but this was one of my earlier forays into quantity cooking.
One of my first days there he had me make buttercream frosting. Now, bakery frosting doesn’t actually use butter (because it tints the frosting slightly yellow) but shortning. This in and of itself is not a big deal. However, I was making 20 pounds of frosting at a shot.
So I take the shortning, and the sugar, and the vanilla, and the secret flavoring, and start mixing. Everything goes well; I scrape 20 pounds of frosting out into the storage bucket. I take myself & the tools to the sink to soak, and lick some of the frosting off my hands on the way. I wash up, head back, and start another 20 pounds of frosting.
Follow the same as above, including lick some of the frosting off my hands on the way to the sink. Repeat again for ANOTHER 20 pounds of frosting.
After I’ve completed 60 pounds of frosting, I begin working on something else. And realize that I am slowly starting to feel nauseous. Very nauseous. I go to the rest room, thinking it’s something else. I try to eat a sandwich, thinking maybe my blood sugar is low. (HA! It was probably through the roof!)
Finally, I can’t stand it anymore, and end up leaving about 2 hours early, whereupon I go home and lie on the couch moaning for about another hour. I couldn’t eat for the rest of the day.
And I never licked frosting off my hands again.
To this day, I generally can only manage to have one piece of cake, etc., due to the aftermath…which is good for my diet. 
It was…a learning experience.