Our days are filled with a constant stream of decisions. Most are mundane, but some are so important that they can haunt you for the rest of your life.
A recent study from Columbia University found that we're bogged down by more than 70 decisions a day. The sheer number of decisions we have to make each day leads to a phenomenon called decision fatigue, whereby your brain actually tires like a muscle.
A new study from the University of Texas shows that even when our brains aren't tired, they can make it very difficult for us to make good decisions. When making a decision, instead of referencing the knowledge we've accumulated, our brains focus on specific, detailed memories.
For example, if you're buying a new car and trying to decide if you should go for the leather seats, even though you know you can't afford it, your brain might focus on memories of the wonderful smell and feel of the leather seats in your brother's sports car, when it should be focused on the misery you're going to experience when making your monthly car payments.
Since you don't have memories of this yet, it's a hard thing for your brain to contemplate.