Edit: On a re-read, I am calling BS on most of her story

If I judged myself by my peers' successes I would be really depressed

Wait... I do and I am

Well, poop

I had a friend talk me into checking up on what might have been cancer. I just did not feel it was in society's best interests t bother saving me

Intellectually I know damn well better

Problem is depression does not trigger off logic, it triggers on emotions. Emotions are fast, immediate responses. Evolutionarily, a faster response is better (from a time when emotion responses were mostly "oh, crap, a tiger!")

I can drag myself out of my funks intellectually, eventually

The problem is a rational argument takes time. Logic is built, arguments are set on each other, building the structure

Body doesn't like wasting resources. Better to have the quick emotional response. The problem is our emotions evolved on the African Savannah 250000 years ago and have never really adapted to civilization

Always try to remember that, when your brain says "what's the use" it is a maladaptive response to our mere 5000 years of civilization, our monkey brain trying to cope with input our ancestors were not ready for and we, for the most part, are barely