My mother-in-law says that every crazy man has his theme song. This is mine, so it will be my first post.
Sundays are special. Every Catholic knows the necessity of hearing Mass on Sunday, but there's more to it than that. There's a deeper, wider, more profound richness to the life of a Catholic family on a Sunday. Sunday is a day set aside for prayer, rest, recreation, and family -- the little images of the Church which God has given us for our sanctification.
In celebrating Sunday, what we don't do is perhaps as important as what we do. Because it is a day of rest, we don't do work. In order that others might be free to rest as well, we don't require them to work; we don't shop or buy things (except in cases of real necessity, like a sudden illness requiring medication), because this would require someone else to work to keep the store open and sell to us. Besides, how can we enjoy a little taste of heaven on Sunday, when we are tied down to the cares of this world, among the first of which are the getting, saving, and spending of money.
Sunday is a little bit of heaven. The seven days of the week of the old covenant represent time. The seven days of creation were repeated over and over and over, until Christ came and broke the cycle: rising early on the day following the seventh day, He opened the door to the eighth day, which is eternity. Therefore on Sunday, we ought not allow ourselves to be bound to time, but to guard carefully the privelege of the baptized soul to fly to God, and bask in the promise of eternity.