How are we a product of our environments and our minds?

Guns, Germs, and Steel by Jared Diamond makes a central argument that Western Europeans were the powerful group throughout history not because they were better than those in the New World, but because they had the resources to succeed, and having those resources was pure luck. While I did enjoy the read, my central problem with Diamond's argument is that he ignores human achievement. His argument on geographic determinism makes it seem that anyone who grew up in that environment could do what, say, Napoleon did. So let me ask: what makes us special?

Now in my third year of college, plans for the future are at the forefront of my mind. I am a firm believer that I wouldn't be who I am today and where I am today without all my experiences: the good, the bad, and the indescribable. According to theorists like Tulving, episodic memory is a system that allows us to retrieve our past, and to imagine our future. It is focally related to the self as a person -- these are memories of the person, not just mere knowledge, or mere reflexes. They are autobiographical. In some sense they are the person.

If Tulving is correct and I am my memories, that also includes memories of my hometown. As Diamond argues, and I agree, the resources around me have without a doubt contributed to my current state. While Tulving's findings are no argument to dismiss Diamond's claims, it does bring to question this: if someone else lived an identical life to mine, would they see the world the way I do? If they saw everything I've seen and learned everything I learned, would they be able to do the things I have done?

No. I'd like to think my thoughts and my ambitions makes me different than everyone else. You can live my life but you can never truly understand my every thought. What, then, allows me to understand myself? How can the mind think of the mind? Well, I don't know. That's why I am taking a psychology course. But I would like to know what factors contribute to the making of world leaders and pop icons. While the environment and resources (or lack of) of childhood play a role, our mindset may be the greatest division: what we think of, how we think of it, what we want, what we think we do/don't deserve, etc.

So I ask again: if the person to your left lived your exact life down to the last breath, what makes you you and not him/her?