Crossing into the Mind of the Male

As I'm drafting my Oxford story, I've realized that for it to function properly, it must be in the first person. When I mentioned this to my father (I often press-gang him into being a sounding  board) he said, "But your main character is male!"
I suppose there is a gap, a divide that one must cross when writing from the perspective of a character of a different gender. However, I'm not sure if there's any more of a gap when you're writing from a character of a different ethnic, economic, or cultural background. Though I believe most writers leave markings of themselves on their characters, most of us would say our characters are quite distinct from ourselves. This certainly breaks that age old trope that everything is autobiographical, though fifty years from now, undergrads will try and apply that theory to your work in essays they wrote the night before.

This will be my first time writing such a lengthy piece from a male point of view. I've decided not to make a fuss about it. I think that if I over-analyze and try to "sound masculine" that it will feel artificial. I just have to be true to the character. Maybe I have some confidence because I've been around men all my
 life. I grew up with a pack of brothers, have mostly male friends, and I am a daddy's girl. I feel like I have a small advantage over some females when it comes to how men speak, think, and interact.
This character in particular also fulfills a sort of Nick Carraway role. Like Nick in The Great Gatsby, Ben (my character) is in many ways, an observer. He's an outsider and we gain insight into this world through his introduction to it.