The Baader Meinhof phenomenon, also known as the Frequency bias, is the effect where something that you learn / hear about suddenly starts to appear all around you. For instance, you may hear about a certain car while talking to a friend, and suddenly you start noticing that model of car everywhere you go.

That's crazy, right?

No.

Humans evolved to conserve energy so that they could live longer by consuming less calories. We are constantly receiving information through our senses. As long as we are awake, we are seeing, hearing and smelling things every second. If our brains were to process all of that incoming information all of the time, then we would need orders of magnitude more calories to sustain that.

Instead, we have evolved to tune out that which is not relevant to us and only keep an eye out (or a ear out or a nose out) for that which is important.

But, how do our brains determine what is important in the first place?

That's where the Baader Meinhof phenomenon comes in, at least partially. Whatever is an object of our conversation, the brain tends to bump up the importance of that and then our senses are attuned to identifying anything related to that as we go about our lives.

Which is why, even though we likely see that car model just as often before we talked about it with our friend, we never really paid attention to it because it wasn't important. But, right after the conversation, it becomes a lot more important and we now start to notice it.

What does this have to do with writing down goals?

Well, if we write down our goals and read them frequently (daily even), then we are bumping up the importance of these goals in our brains. So, when we come across any relevant opportunities, we notice it and pay attention to it rather than simply let it pass by like a lot of other information does.

This drastically increases the odds of us hitting those goals.

So, write down your goals, and read them frequently.