I Am the Cheese Theme of Versions of Reality

What is real for Adam? It's impossible to say. Often in literature we see characters whose versions of reality differ from those of the people around them. In I Am the Cheese, Adam experiences different versions of reality within his own mind. Before the accident he consciously witnessed reality changing around him when he discovered that his family was part of the Witness Re-Establishment Program. After the accident he doesn't even realize that he's experiencing different versions of reality.

1. In which reality is Adam the happiest? Does it matter?
2. How does our impression of Adam's bike ride change after we've finished the book? Is it harder for us to accept that it's a reality for him when we learn that it takes place in his imagination?
3. Speaking of versions of reality, is it possible that Adam's bike ride isn't just his imagination but a dream?

There is one reality, shared by all humans. That means Adam is removed from reality.

Reality bites. (Or, put more eloquently, reality is never as romantic as the world of our imaginations.)