Dream or reality
Have you ever wanted to control your dreams? Be able to do anything you wanted; go into space, work as an international spy, maybe even fly? There are some theories, that let you control your dreams. Some are more reliable than others.
There is one theory, a more realistic one, that says if you write a bold R on your palm and check it is there often, it will become a habit. It is thought that once this has become a habit you will check your hand while dreaming. Because the "R" stands for reality, if its there you're in reality. If its not, then you're dreaming. Once you have realised it is a dream, you should be able to control it and do whatever you want.
The key to doing the impossible in a lucid dream is belief. If you believe you can fly, you will. If you believe you're a spy, you will be. If you can believe it, you can dream it.
But there is a risk you must take. There is a small possibility that you could get confused. About which is which. You wouldn't know if it was dream or reality. Maybe the "R" on your hand gets washed off in the shower and you think that reality is a dream. For all you know, it could be.