Left handed people are the only ones in their "right" minds.
My father is left handed.
I am left handed.
My oldest son is left handed.
* In baseball and softball, it's well-established that hitters tend to do better against opposite-hand pitchers. Since most pitchers are right handed, lefties have an advantage. And you have a shorter run from the plate to 1st base. It's a small difference, but it's there.
* When working at a computer - if you can learn to use a mouse right handed like others do, you have the advantage of being able to take notes with one hand while mousing around with the other.
* 7% of the population is left handed, compared to 20% of Mensa membership.
* He'll be in the company of such famously successful left handers as Paul McCartney, Jerry Seinfeld, Bill Gates, John McEnroe, Helen Keller, HG Wells, George Burns, Larry Bird, and Four of our last Six US Presidents.
* The world is made for right handers. This forces lefties to learn to do a lot of things with their right hands as well as left. It stretches our brains. It's thought to be one reason why left handers seem to have a greater spacial awareness and higher average scores on intelligence tests. Also, why left handers recover better from strokes and other brain injuries than.
* The world is made for right handers. Teach him to use right handed scissors. It's just easier than finding the lefty version. There are a lot of other things that come up that he will just have to learn to get around. In college lecture halls - you know those ones with the tiny flip-up desks - only the one desk on the far left end of each row will be made for left handers. Maybe 1/20 seats or even less. With 1/7 students being left handed, you learn pretty quick to either take notes turned at an awkward angle in your seat, or to get there early enough to get a left handed desk. When writing, your hand tends to rub over the words you've just written and smudge them. I had a left-handed teacher in 6th grade who finally taught me how to write with my hand below the words and it made a huge difference.
(When I was in 3rd grade and learning cursive, I solved the problem by writing backwards. Drove my teachers crazy. They tried to say I was dyslexic but my mom shut that down pretty quick and told them they shouldn't be punishing me for being able to do my lessons frontwards AND backwards when the rest of the class was having trouble just doing them one way!)