I am middle aged and when I was in high school, college, and grad school, there were very few really smart girls. All my competition was from other boys. But now that girls are kicking the snot out of boys in virtually all realms of academia, there simply by plain stats had to have been really smart girls in my classes years ago who simply must of held it back, maybe to feel accepted. The brain power had to be there, it was just hidden. Now girls don't hide it. They excel.