Is it normal to like cats bum?

It all started when I was 11yrs old. My older brother was always showing off to his mates, and most of the time, he did this by embarrassing me. His mates would hold me down, and he would grab my Mums cat, and hold its tail in the air. He would lower the cats bum down onto my face, while shouting "cats Bum". This happened many times. I am now 25, and a few years ago, I was looking after my friends cat, while she was away. The cat liked to eat KittyKat, and it had a certain smell. It must have stirred something inside me, because I could not stop thinking about cats bum. I had a little play around with the cat, and ended up licking its back end. I liked t so much, I ended up getting my own cat. Sometimes I feel like a freak, but when Im actually engaging in "cats Bum", all my worries go away.