OF MICE AND MEN presents a story that the migrants faced in the 1920's. Today the same four themes pervade our society to the same extent. By delving into these themes that Steinbeck presents, you have become aware of the injustices and hardships that mankind deals with.
It's the same for understanding a topic as broad or complex as the mystery of human existence: when you only know part of the picture, you only know part of the picture. Now you all know a lot more. Nice work. You should be proud of yourselves! How can you use what you've learned to see beyond the black and white of a topic and into the grayer areas? What other parts of the mystery of human existence could still be explored? Remember, learning never stops.