You've just said what I said
Unfortunately it's perception that defeats us everytime in these matters.
Just like the innate human desire to label everything, to measure everything the smallest degree. Our brains just can't deal with the idea that something may just 'be' or may be infinite, as in existing forever, it's always been there and always will.
It's a trait that has led to some amazing achievements, as without the inquisitive nature we wouldn't be as technologically advanced, nor mentally advanced as we are.
No matter how far advanced we become, I fear humanity will be no more and will never fully answer the questions posed in the opening post of this thread.
To my mind, a slightly depressing, yet awe-inspiring thought.
ps. spending 10 hours a day driving your rattly tincans around all day gives plenty of thinking time for these things - I may be no philosopher but the whole subject fascinates me endlessly.