Please help me i dont understand the questioned asked for my assignment on the great Gatsby.Please help?

Question

He had come such a long way to this blue lawn, and his dream must have seemed so close he could hardly fail to grasp it. But what he did not know was that it was already behind him, somewhere in the vast obscurity beyond the city, where the dark fields of the republic rolled on under the night." What do they mean about its already behind him??

Answer 1

I have not read this novel, but there are a number of online study guides, and quite a few other resources on the web that can help you with this question.  Most of them have quite a bit of good information.  Have a look at these, and you should get some help with your work.  If you do a search you will find many other links.  

I would interpret "already behind him" to mean it had already happened.  Best of luck with it.