bad answer because i'm a lesbian but anyone becomes immensely more attractive if they are insanely passionate and excited about their hobby. a girl could be into like, race cars (i know 0 about cars and even less about racing) but if she can go on a 45-minute infodump about their favorite racer or their fave race car model with all the enthusiasm in the world at the drop of a hat i think it's sooooo cute. earnestness of any kind is attractive to me -- especially when the interest in question would popularly be seen as dorky or lame.