Christmas. Even if you aren't Christian, you probably celebrate it at least a little bit. It has become the secular symbol of consumerism, and unfortunately, I am played HARDEST by the corporations who want my money.
My issue is simple. I simply have NO sense of money management when Christmas rolls around. It's absolutely ridiculous. Any other time of the year, I am hard-pressed to buy ANYTHING because I am the most frugal, penny-saving freak you will ever meet.