When you have similar interests with someone of the opposite sex, you are more like that person than those of the same sex as you who don't share those interests. Gender does not dictate interests or talents, and it certainly should not dictate who your friends are. The adults may have separated the girls and boys when you were growing up to make it easier for THEM, they may have even tried to make you believe that girls and boys are two different species, and as dissimilar as birds and rabbits~ just like they tried to make you believe that a cold is not a virus but is caused by cold air~ but we are adults now, free to choose who we spend our time with for ourselves.