Very long nipples
I'm a Taiwanese woman. I grew up in a very secluded environment. I had my first sexual relation when I was 22 and even then the only nude people I had seen were my two sisters. We all have very long nipples so I always thought that all women had them like that.
I moved to the US at the age of 23 and like many people who come from other cultures, I opened myself to s** for a few years. Once here, I had a total of 8 sexual partners including my now-husband. Often I was told that they really liked my b****** which was strange to me because they're very small (I'm a size A).
It wasn't until I was 25 that I found out that my nipples were actually special. :) I started going to the gym in my local YMCA and the first time I took a shower there, I was shocked to discover that I was the one who looked different. I finally understood why guys found my b****** attractive.