Answer:
Two in a whole and four in a pair. And six in a trio you see. And eight's a quartet but what you must get. Is the name that fits just one of me?
I am the hole in the night, the ever watchful eye. I return in a cycle, to enlighten the sky.
I am the third from a sparkle bright, I thrive throughout the day and night. Deep in the path of a cows white drink. I've had thousands of millions of years to think. But one of my creatures is killing me. And so the question I ask to thee, is
Not a burden for its weight and daily carried out, He who takes it wishes it had never come about
I'm light as a feather, yet the strongest man can't hold me for more than 5 minutes.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.