As a Recovered Catholic I still resent all those meatless Fridays. In school they served some awful dry white fish, bloody and unbreaded. I usually made do with a peanut butter & honey sandwich.
At home we usually had fish sticks, which were OK. Mac & Cheese and meatless spaghetti were other Friday staples.
The thing is: there was no SIN involved. Officially it was all voluntary - but for some reason everyone seemed to think it was a matter of faith and morals. We figured, eat a burger, go to hell. No wonder I turned atheist in my teen years! I'd never make it as a vegan.