We can only answer one question per post. Please re-post your question about the title of the book separately. Here is a response to your theme question.
Keep in mind that identifying themes is a personal thing. Different people can come up with different answers to the same story. There are not five "right" answers to this question.
Five Possible Themes for Of Mice and Men:
- People who are insecure about themselves tend to look for others to belittle. It makes them feel better about themselves. (Curley and Lennie)
- We cannot look to others to make our lives meaningful, we have to do it ourselves. (Curley’s wife)
- A dream can give people the strength to keep on trying (George and Lennie’s dream of owning their own place)
- True friends sometimes have to make hard decisions to do what’s best (George’s decision about Lennie at the end).
- Some people are not equipped to handle the difficulties and cruelty of the world on their own. (Lennie)