Simple neurology explains why it happens actually so we don't even have to dive deep into Carl Jung's theories that Americans know as "MBTI" lol.
Everything triggers your brain and thus it causes chemical reactions. Because of it, for example you read this message and can understand it because your already existing neurons that are active are being simulated due to relation of the information your brain process. Thus you can remember what these words means and thus related information triggers related memories. So when I talk about "Saturn" you remember related information but when I say "Zabaluba" you would be like "WTF is that" unless the word is similar to a word you know but I made it up so it shouldn't mean anything lol.
So, active neurons acts like the data in RAM and thus they effect your "CPU" so these information is constantly processed like an open program like your web browser. Because this program is "active" your brain notice anything that's similar to this program. So ability of memory and pattern recognation goes hand to hand.
That's why when you learn something like a word you start to notice it more way more than before. That's actually because your brain generates a reality to comprehend real life, so to do this it using information from your active memory to build the fundamental blocks of your reality. It means what you understand in real life and what you notice in real life depends on what you know. For example when you were little like 4 years old you didn't think about life in terms of money and criminals, your whole reality was so simple it was about yourself like your parents, the food you eat and your toys. When you were teen your reality started to be about opposite gender, sex, being better than others, worry about future and all. When you were adult your whole reality was about how to survive this month and trying to save money. When you were an old person your whole reality started to be about your health and trying to understand what happening to your body while still trying to live your life in a way you don't waste it. When you get way more older your whole reality started to be about simple peace and living one more day and sometimes you think "ah today is a good day to die but alas it seems I'll breathe for a while so I better get up the bed" and you live your every second being alert of any time you may just die in a way "ah my angel of Death where were you my friend?" lol. And when you really get old and old your whole reality started to be about there is more to life than being a human and having human concerns. Is death the end? You realize the life people don't live is the actual death. Their life never started because they are not really awake!!!
As you see, the degree and content of reality depends on what you know and what you recently started to think about as what you know changes the way you think. Hence, think about "number 23 with Jim Carey", make the idea of the number 23 your active memory and then you would notice number 23s and in this context Jim Carey everywhere. This is like how kids start to talk about a topic they just learned in the class. After geometry class no wonder you may start to see shapes everywhere and pay more attention to triangles, squares and whatnot in our lives!!!! lol. And then some people forget sun exist then day and night becomes more about change in colors and lightness. Who actually think and remember Earth actually rotates? People even forget they live on a planet because we are more focused on other stuff until we remember basic facts lol. I personally know a person who sometimes forget gravity exist lol.
Well after all these said I have to make it clear brain works in the way it filters information to optimize your attention. So when you are chased by a monster your whole reality will be starring the monster as the lead actor while your whole story will be about how to survive. When this happens you won't notice a horse twerking in the background even if you had saw it lol. Well your brain will notice but not your mind.
