Mendelian Genetics... why can I flip my eyelids?

During this week in science, we started researching Mendelian genetics. In our research, we have studied certain genetic traits in our families. Those traits include, being able to roll ones tongue, having a widow’s peak, hitchhiker’s thumb, and attached or unattached earlobes. After researching what traits my parents have in comparison to my own, I can determine some of my own genotypes for these traits. First, I tested their ability to roll their tongues. My dad could, whereas my mom could not. Because this is a dominant trait, I know that my mom is homozygous recessive, and both my dad and I are either homozygous dominant or heterozygous. Next I found if either of them had a widows peak.  Like myself, my mom does not, however, my dad does. Because this is a dominant trait, my dad is either homozygous dominant or heterozygous, and my mom and I are homozygous recessive or heterozygous. After that I determined if they had attached or unattached earlobes. My mom’s earlobes are unattached like mine, but my dad’s are attached. Having an attached earlobe is a dominant trait; therefore I have to be homozygous recessive or heterozygous. Finally, I determined if they had hitchhikers thumb or a straight thumb like myself. Both of them have straight thumbs, and due to the fact that having a hitchhikers thumb is a recessive trait, I must be homozygous recessive. Although this was an interesting study, I wasn’t really surprised to find that I am a mix of both my parents. However, the one thing I did find interesting was the fact that I can flip my eyelids back over themselves, but no one else in my family can, not even any of my cousins, aunts or uncles. I’m guessing this is a recessive trait and I wonder if some past relative of mine was able to do it as well, and if it comes about in our family ever so often???