How do you find the willpower to give up things so totally?

The Catholic tradition of lent has always been interesting to me, one is called upon to give up something one really likes (or adopt a new behavior) while eating less and not making a show of it- a bit like a New Year's Resolution with a built-in stop point. I decided growing up that I would give up something new every year and everything given up in previous years as well. This becomes sufficiently annoying over time that one eventually just gives up the behavior all together unless there is a special circumstance. So far the list has been:

Fighting with my younger sister
Candy (which I added an exception for in one square of dark chocolate)
Ice cream
Non-educational television
Pizza
Pop
Restaurant visits without occasion
Buying Bottled Water
Buying Video Games
Elevators
Buying Cheese and All Cheese Containing Foods
Plastic Containers in the Microwave (plasticizers are carcinogenic)
Table salt
Chewing Gum (ghost calories)
High-sugar fruit drinks
Buying Red Meat

One day when I'm older I am going to go back and do everything on the whole list to that point in one day, and it's going to be quite a party.