When you think of insomnia you're thinking of someone who can't sleep for a reasonable amount of time. A typical complaint from an insomniac is not being able to close their eyes or rest their mind for over a few minutes at a time. There are many reasons for this ranging from anxiety to bipolar disorder. Yet sometimes there's no real causes and can just happen for any given reason, but too much activity and physical pain can be causes for someone not to be sleeping at night.