I still wonder when the first androgyne will jump into this thread and ask: "Opposite gender? WTF is that?"
Oh, there is one thing I don't understand about guys: their huge interest in cars and how they can talk about that for hours. I'm not interested in cars. I even have a specific phobia there: when I have to drive a car, I almost get panic attacks, such as other people when you put spiders on them etc. (As a passenger, I have no fear.) Somehow I managed to get my driving license, however, but after each teaching hour in a car my t-shirt was soaked wet with sweat, I could almost wring it out. I haven't been driving much since, and not at all in the last 12 or 13 years.
But this frenzy for cars might also be a cultural thing. The Germans are crazy about cars, for the French it's just a vehicle which helps you get from point A to point B. Cars in France are often in a horrible condition, with buckles and dints everywhere and when the paint is scratched off somewhere, they tend to use a random paint they have at home to cover it so the car won't rust, may be brown on (original) white paint etc. For Germans, on the other hand, cars are a status symbol and they are usually very well taken care of. I grew up in a French household in Germany, and my dad and most other male relatives always considered cars to be just a vehicle, and my female relatives were the same.
There are other examples like this which depend on the culture. So if you grow up between two cultures (or subcultures), you find out that many of the so-called gendered interests, mentalities and behaviors are not gendered at all or their gendering depends on the culture. If you're transsexual, it either makes things more complicated to see in which gender box you fit it once you're in your self-discovery phase, or it makes things easier as you don't try to harshly to fit into the new gender box as you can pick things from two boxes depending on the topic even if you don't choose to do what's right for YOU. Or you have both effects at the same time. Hm, I might open up a new thread on that subject.