Why some have it in them and some don't.

I have spent much of my adult life wondering why some choose adversity and challenges in their life as a stepping stone to achieve greatness whatever that may be in their own lives while others use it as an excuse to check out. Let's face facts, none of us have been spared our share of pain or suffering. Some of us hide it, some of us flat out lie about it and some of us pretend it does not exist at all. I myself used to be one of those simpy Stepford Wives kind of women, smiling at everything popping Prozac and wondering if this was really all there was. I have never been prone to depression and I do understand that it is a very serious condition. I also feel like in America at least, we are afforded the luxury of having these conditions. I highly doubt if we were hunting for food for our family for the day in Zambia and if we were not successful our children would not eat, we would not say to ourselves, "Meh I'm depressed. I'm going to lay in bed all day." This is a luxury not afforded in survival situations. What makes some people comfortable in mediocrity and others willing to suffer to the bitter end to risk all to do what they want?
I think several factors come to play primarily Heart and genetic code. You have to have the hunters heart. I do not mean that in a Good Ole Boys Club or football way I mean you have to believe in something and want something so badly that you will burn every single bridge to get it. I movedto NYC at 22.i knew one person and had no job. My parents were sobbing at O'Hare and told me if I left I was cut off financially. I was terrified. I did not know in this moment what would happen. I knew one thing I was NOT going to come crawling back home so I worked 3 sometimes 4 jobs in NYC during those years. I was exhausted sure but I was 22 who cares. Still managed to go to grad school at NYU hold down my job and prove my parents wrong. I learned a lot about myself during that time. I saw a lot of friends flip out, lose it, two overdosed and died. No matter how much pain, no matter how difficult, I never stopped. I never looked back. I didn't have that luxury. In retrospect, I've never had the luxury . I've made my choices and have proceeded with my life based upon them. We all do.
I see sharks and I see guppies. I don't necessarily think we all need to be sharks or alpha males don't get me wrong there needs to be balance and to each his own. I guess I am just an advocate for taking that risk, burning that bridge, leaving yourself no other option BUT doing what you really want to do, what's the worst thing that can happen? It cannot possibly be worse than sitting in a cubicle for 30 years at a mediocre job you detest.