Have you ever checked the time right before you start eating?
I do, every time I'm at a new restaurant. If there's even a concern that they might contaminate my food, I want to know as soon as it hits me. It usually hits ~1 hour later, so I check the time. Then, when my stomach hurts or I can't focus, I check the time again. And when I see that it's almost exactly an hour later, I get a sinking feeling in my stomach. A "here we go again" as I prep for another awful, terrible, no-good week where I struggle to function.
I also use this tiny window to get home as soon as possible. Before the symptoms really kick in, and it's still safe for me to drive. (In case you're wondering, imagine staring at a traffic light and taking a couple seconds to figure out if the light is green or red. If you're stopped dead and you don't realize the light is green, that's fine. When you're going 60 and it takes 3 solid seconds to realize you're approaching a red light? Yeah, not fun. I've also experienced several moments where I forget which pedal is the gas and which is the brake.)
Paying attention to what time I eat uncertain foods is just one more unexpected side effect of having Celiac Disease.