You know I suspect that we will know the purpose of our existence when we are on brink of achieving the purpose. Maybe our purpose is to destroy the universe - to take entropy to its max value. Imagine a scenario of those final moments as we try helplessly to restrain the ultimate terrorist scientist from pressing the big read button. He himself realises (of course after pressing the button and watching the explosion wavefront approach him) "dammmmnn! Instead of screwing the case for everyone, i actually achieved it for all of us... Faaaaaakkkk....."