I don't know about older men but I've always found nerdy girls attractive.
If you are a young girl, regardless of your personality, older men ARE interested in you. And, most of the time, it's because they are too immature to impress women their own age and so they prefer to exploit young, natve girls.
Older men and women are less shallow, that's why. They start to see that a person's real attractiveness is more than the things you see at first glance.
Yes its not always about being a nerd, don't lable yourself i'm sure if you carry yourself well you will be fine