In most cases, you won't die if you don't dream. Many people don't get sleep for many days. For that matter, many people do not dream. Instead of dreaming, they instead see short pictures in their mind all about what happened that day. It is called "Sliding". If you do not dream, you may get more grumpy, and more likely to lose breath when running quicker, but you don't have to worry about not dreaming. It is a very rare accurance to die if you don't dream, but if you don't dream often you may get dissy, and do the things above. But it's okay, just get some extra sleep and you will be back to normal.