Nothing Gold Can Stay

I had trouble understanding this poem so I looked it up to see what it meant. I apologize for this but i read it ten times and i couldnt understand what Frost was telling us in his poem. Some people said it symbolized the cycle of life and i can see how then can think so. "Nature's first green is gold," I believe this would mean the beginning of a new life hence, the beginning of the world. "Her hardest hue to hold" would probbaly mean the difficulty of starting a new life or the starting of our world. "Her early leaf's a flower" could mean the first humans on earth. "But only so an hour" could mean the first humans wouldnt be alone for long and there could be more on the way. "So leaf subsides to leaf" could mean more humans are born and thus the first humans have more company or they have their own children. "So Eden sank to grief," now I couldn't decide on this part on what it meant but I think it would mean the gold in the nature has disappear because it has gone to green. "So dawn goes down to day" could mean as days pass, and "Nothing gold can stay" could mean the world isn't as gold as we think it is so nothing is the same. So all together I believe this poem means we come into this world alone and hoping life is all fairytales and thus it would be easy. As we grow up we meet people who will dissapoint us and thus we see that life and the world is not as easy as we thought it was.