Because I am left handed, I have done a lot of research on the subject. Some of the things the average person may not realize are:
1. One out of ten people are left-handed. Out of these, 2 out of 3 are males.
2. Left handed people have more accidents. (Probably due to machinery being constructed to accommodate right-handed people.
3. Many every-day items people use are inconvenient for left-handed people. (Steam irons often have the cord on the wrong side; most scissors are made for right-handers: many classrooms, especially in colleges, still have right-handed desks very awkward for a leftie; calculators have the function keys on the right side; guitars and other stringed instruments must be re-strung backwards if you want to play with your left-hand; some car doors are very hard for a left-hander to use, etc.) The list is much, much longer, but you get the idea.
4. At one time in our history, left-handed people we put to death as left-handedness was considered evil.
5. Studies show, that for some reason, left-handed people, on the average, do not live as long as right-handed people. The reason for this may be that it is a bit awkward for a leftie to live in a right-handed world. This leads to more accidents, and, therefore, to more premature deaths.
Being left-handed DOES make a difference.