Great Expectations

When reading the passage Great Expectations I found it very confusing. Words that I thought should not be in the same sentence as other words were, like on page 115 where it says, "It was in this place, and at this moment, that a stange thing happened to my fancy." What is a fancy? I really did not get what was being said, and I still don't. I also realize that starting from a random chapter is hard to do, because you may not know what is going on.