Mere exposure is a leading factor in making friendships, who could have thought of that? But that’s not the only effect of mere exposure. It basically might be the reason you never understood of why or how you like a particular thing (e.g. a song or a picture.)
You see that incoherent painting you have hanging in your living room that doesn’t really illustrate anything significant, and you only keep it because your parents chose it for you? You never really liked it at first, did you? But now you just cannot see your living room without it. Well, you now like it hence that. The mere fact that you are exposed to it every single day is an enough reason for you to like it!
Incidentally, this could also be the case in your social life. If you look back you will realize that you might have befriended certain people just because you saw them every morning in the bus station or the metro. You feel a sort of recognition as you see them every day, and you start chit-chatting after awhile. After that you scribble down each others’ numbers and you start hanging out together. Just like that because of the mere fact that you met every morning while going to school or work.
This all goes back mainly to the fact that you are now familiar, and you positively recognize that particular person or that particular thing.
This is just another interesting fact of the human nature. You can use that to your advantage. You can go ahead and start a chat with the cute person you see every day, but never really get a chance to talk to, and she/he won’t think you are weird or anything. Furthermore, that’s a reasoning for you. So, the next time someone asks you why you like a particular thing, you’ll know what to say!