What is Nick's view of repeating the past, and what is Gatsby's opinion? Why is Gatsby's opinion unrealistic?

Nick believes that you can't repeat the past because it has already past...... it's over. Gatsby believes that the difference in his circumstances can change what happened in the past. He cannot get a grip on the fact that the past is dead and gone. Having all of the things that he believed kept Daisy from being his in the past in his own mind are now negated by his present situation. 

No