@calonso Said Jeeze, what is it with every one trying to reduce us to basic animal instincts? Just simply surviving has never been the sole purpose of human living, infact, it's hardly ever enough. Think about all those people who have everything and still commit suicide, what's that all about? What about the need to do something significant and leave a legacy, immortality? That's goes way beyond just surviving. Then there's our dire need to express ourselves or difine ourselves musically, artistically and philosophically, what animal do you know does that for purposes outside of mating rituals?
I think people that try to simplify human existence by comparing it to animal survival instincts are just unwilling to accept that there is something more to us, something set apart, something very unique and maybe even spiritual.
I'm not touching the suicide question with a 10 foot pole to avoid a flamewar, I can however, answer your other questions
To leave a legacy, express ourselves, musically and artisticaly. Think about it. The one major difference between humans and other animals is our massive brain. Where animals can get a mate by showing off muscles, having the prettiest feathers, the brightest colors etc, we use our big brains to do exactly that, only a lot more complex. we individualise ourself by expressing ourselves in the above, to rise above the rest - to show our "feathers are the prettiest" if you do something and you commit to it, you want to be the best at it right?
Same goes for a person who wants to make a carreer, to become the head of a big company. such a person strives to be the "alfa male" in our "wolf pack". Why is it that "nerds" get beaten up by the bullies? they show of weakness and the bully, who thinks himself as strong wants to show of he is strong by taking out the weaker persons, to show of supperiority.
The real problem is that every decision is influenced by our sub conscience. no one is aware of this, no one CAN be aware of this, everyone thinks all their decisions are 100% consciently made and maybe for improving or helping mankind, but they are not.