I haven't observed Shrove Tuesday (Mardi Gras) or Lent for many years. I believe it was meant to use up any milk, butter or eggs which would have been given up during Lenten fasting. Even being raised Catholic, we ate normally during Lent.
I guess it's more of an excuse to celebrate pancakes, which I do love. I haven't made crepes in years, since my pan is cast iron and my stove-top is glass. I should look for a lighter pan, and treat the GC. We always had ours with brown sugar and extra butter.