There are a few perfect people in the world, the rest are right handed.

Austrailian researchers have recently found that left-handed people tend to think more quickly, and the speed increases the more left-handed a person is. Left-handers tend to use both sides of their brain more often, increasing the rate at which information can be processed. The researchers did tests on very left-handed, mildly left-handed, and right handed people, testing the speed at which they could identify matching letters in the right and left visual fields. Since left-handers responded with a shorter reaction time researchers suggested that they use both sides of their brain to interprept language. Reaction time improves over time because both sides are consistently being used. This implies that left-handed people are instinctively better at activities that involve both sides of the brain, including computer games, certain sports, driving in traffic or other activities involving mulitple stimulus processing.

http://news.bbc.co.uk/2/hi/health/6212972.stm