Why did my sexual preferences change ?

I'm 20m and before I was 16 I had a preference for women with big breasts and butts. I would go on porn sites and look at milf porn or women with big breasts and butts.

But when I was 16 I started to look at porn actresses that had small breasts and butts. There was one in particular that had a pretty face. I wasnt attracted to her that much at first, but there was a video where she was oiled up and i thought it was sexy. So I kept masturbating to that video.

Eventually I developed a preference for women with this body type. I also feel attracted to preteen girls. Nowadays i only feel attracted to women with small breasts or preteen girls.

When I look at women that I masturbated to before I was 16, I feel turned off looking at them. Why did this happen?