People who sleep on the left side of the bed tend to be more cheerful than those who sleep on the right side of the bed. That's what a study of 3,000 adults sponsored by the British hotel chain Premier Inn. The study found that those who sleep on the left side are not only more cheerful, but also more positive and capable of tackling heavy workloads and a stressful day ahead. Those who sleep on the right side of the bed are less likely to wake up in a good mood.
Oh...and below is what your sleep position says about your personality.