I just read a great article on making decisions and how our decisions change based on what we do during the day. The idea is that people have a real limit to willpower and the ability to resist temptation and if that willpower is tapped during the day then later on we simply don't have the capacity to make good, informed decisions anymore.
The really useful thing I got out of this was the idea that you can actually make yourself into a better decision maker by simply cutting out opportunities for things to come up that drain your willpower. All those little tricks we use to keep ourselves away from temptations like compulsive web checking, sweets, or whatever else that taunts us are actually powerful tools for improving the quality of our decisions and our lives. Keeping yourself away from McDonalds, Facebook, chocolates or cigarettes can actually cause you to make better financial, emotional and personal decisions throughout your life as well as help with the immediate issues involved. This is the sort of stuff that we should teach in schools as it is about one hundred times more useful to people than trigonometry or Shakespeare.