The point was not to �have to eat fish�, but to abstain from eating meat on a Friday. Although its no l onger considered a sin to eat meat on a Friday (the day Christ died), �good Catholics� still consider it appropriate to abstain from meat on Fridays - it's like a mini-Lent each week - sacrifice/abstain from something (meat) in preparation for Sunday.
It was changed in Vatican 2 (Oct 11th 1962, Pope John Paul XX111)
caz - I don't think you are to eat ONLY fish on Fridays, ie fish for breakfast, dinner and tea. I think you are also allowed to have other things eg bread, cereals, milk, vegetables, rice, fruit etc etc etc
huh i was made to believe it was something to do with Catholics not being able to afford a good Steak! Please do not think this is my opinion, only what I remember hearing from various people when I was young.
I'm half Polish, lived here in the UK all my life, on Fridays my whole family, UK and Poland refrain from eating meat. It's a Catholic thing. However I noticed that in our company canteen they serve fish on Fridays and no meat from the food counters, obviously they still have meat in sandwiches etc, but it reinforces the friday fish question.