Great Expectations: Chapter Nine quote response

I think what a long chain of iron and gold is, is that each chainlink represents a day. A gold day could be happy or brings good tidings, something like that. Iron is cruel and harsh, or maybe just a day that was filled with work or just was plain out bad. Flowers and thorns are a synonym for that, flowers being good days thorns being bad ones. But the first chainlink is something memorable, like the day Pip had in the story. When it says "this never would have bound you if, but for the formation of the first link of one memorable day." That last bit says if it hadn't been for the thing you did on that one day, your life wouldn't have been the same up to this point, or your future would have been altered. I think its saying your life is dependent on how you spend it and what you do.