40 Days and 40 Nights without Diet Coke?

If you're Catholic, and a practicing Catholic, then you know that right now we're in the middle of Lent. Despite my Honors BA in Christianity and Culture, I can't really tell you why we "celebrate" Lent (which when I was little I thought was spelled 'lint,' like belly button lint...that always confused me.) I know it has something to do with Jesus being in the desert for 40 days, so we have to give up something to get closer to God. Well, I gave up pop. Diet Coke, really, but it's the only pop I like, so...Anyway, one thing I did learn at The University of Toronto while I was studying with the priests was that it's OK to indulge in whatever you gave up for Lent on the Sundays during Lent. The first time I heard this I didn't believe the girls who told me. But we asked a nun, and she said that some people believe it's OK because Sunday's are a time of celebration in the Church when everyone should go to mass and drink diet coke. Or do whatever they gave up for Lent. She (Sister Anne Marie) sounded skeptical, though, so I asked Father Donovan the next time I went to his class (of course, this is because I was really interested in his answer, and not because I hadn't done the reading...) He gave me the same answer, but said that he believed it, too. I trust him, so I'm going with it. Plus, I can't go that long without diet coke...