I've long concluded there's no external purpose to life--as in influencing some tangible indestructible entity on whom the act of our living would've an impact. But this sterile view begs many questions--like 'why do we then feel such an intense desire to live?', 'why should we live?', 'what should we do while live-ing?'.
To the above questions I do have some crude answers, which I can of course, not claim to be applicable to all. Greatest reason being there's no measurable endpoint to the act of living. Like endpoint of using energy efficient automobiles would be the reduction of green house gases in the atmosphere, which can be measured.
Well so as usual, as a quirky idea, I searched for 'purpose of life' on Wikipedia, and this is what turned up.
I've not yet read the article completely, may not even complete it myself, but thought others might enjoy it. Reading it won't take much time, but understanding it completely, which will require one to understand concepts right from molecular biology, thermodynamics, quantum physics to abstract philosophical and logical assertions, will certainly take much longer--maybe around a week.
One thing that struck me was how the ancient Greek philosophers born more than 2000 years ago had such clear and objective view of life. They were only limited by lack of scientific knowledge. And then, somehow the world's intellect regressed, and it took mankind almost two millenia to reach their level again and progress beyond that!
Maybe philosophy will always stay ahead of science. It requires only two tools--one harbored behind the two eyes and an armchair!
Which reminds me, maybe, I've been philosophizing a lot, the indicator being creaks of my armchair, which are nothing but groans because of the abuse I subject her (it's my armchair--I get to assign the gender ;) ) to. Time to