Once you become aware of it you begin to see it everywhere.

 Have you ever started liking something that you thought you were seeing for the first time only to then start noticing that it is actually everywhere?

  Until someone I know got an orange color car I had never seen one before. Then suddenly I noticed that there were several in my hometown. 

  Once someone I knew started wearing a bucket hat which I had not seen since I was a teenager. Suddenly everywhere I went I would see people wearing them.

  I thought a turquoise colored phone case was going to make my phone stand out because I had never seen one that color before. Then I started noticing that lots of people have that color.

  Until you look for it, it could be right in front of your face and you won't see it.

  Just because you didn't know about it and had seen it before, doesn't mean it doesn't exist.

  Try it sometime. Pick a specific color or style of an object that you think is rare. Then because it is on your mind you will suddenly realize that it is not as uncommon as you think it is. 

  What you see depends on what you are looking for.