You see this beautiful girl standing across the room. You would like to approach her and start a conversation, but then you think to yourself “Nah, she probably has a boyfriend. Also she wouldn’t like me anyway. Not to mention that I need to focus on studying, I don’t really have time for relationships.” So you look away, go home, play World of Warcraft, eat a pizza, feed your cats, hump your human-sized action figure of Chewbacca, go to sleep, and die alone.

Were your excuses the actual reasons for not approaching? Imagine if you’d know with 100% certainty that you will not get rejected, would you still decide that you’d rather focus on studying?

Rationalization means coming up with seemingly logical/rational explanations for irrational behavior. We do whatever feels good, or whatever is easy/convenient/profitable, and then come up with explanations that make us feel better about our decisions.

Imagine you want to buy a new car. You don’t know much about the recent models, so you research, select a few options, look at their specs, make the list of pros and cons of each one. At the bottom the list, you finally write down your decison.

Now let’s say you’re a salesman, and your job is to sell a certain model. You take a sheet of paper, and at the bottom you write “and that’s is why this is the best car ever”. Then you do your research, compare options, and above the bottom line, you write a list of reasons why that’s the best model.

You are not lying, all the reasons are true, but you started thinking about them after the choice has already been determined. Your answer was already either true or false before you came up with explanations, and they could not change your choice. Your actual reason for making it was “that’s my job to sell this car”.

It is impossible to make a choice or belief rational even by using the smartest, most convincing arguments. The purpose of rationality is not to argue convincingly for a position, but to decide which position to argue for. Once your position is fixed, it can not become more rational. Rationality takes evidence and knowledge and looks for the best, most accurate conclusions. Rationalization runs in reverse, it starts with the conclusion and searches for reasons. If you already know your answer — thinking about it doesn’t matter.

Your success is determined by how good your decisions are, and when you are rationalizing, the actual algorithm you are using to make decisions is “whatever feels good”.