[JesWade21 (OP)]

I'm right-handed.

[Bored chemist]

I'm right-handed.

Me too.

[Lible1997]

I'm right-handed, but I can also write with my left

[HaelSturm]

I'm right-handed. I wanted to learn to write with my left hand, but something went wrong 

[thecatdat]

I'm right-handed, but I eat or open things with my left hand.

[evan_au]

About 90% of humans are right-handed.

I saw an interesting piece of archaeology that looked at hand-prints on cave walls, and deduced that around 90% of these ancient artists were also right-handed.

Some animals also show a hand/paw preference...

https://en.wikipedia.org/wiki/Handedness

[alancalverd]

Lefthandedness is a curious phenomenon. Most things in nature occur 50% of the time or hardly ever.

My theory is that 50% of us are born unable to use the left hand efficiently, possibly due to the enormous demands on the unconscious brain made by bipedal stance and movement. The others, born ambidextrous, have a 50-50 choice, so leading to 75% dextrals by obligation (50%) and  free choice (25%). So the remainder are encouraged by society to be righthanded.

This hypothesis is supported by the gradual increase in the number of sinistrals in recent years, as society (at least in the UK) has put less pressure on schoolkids to conform. Time was you would only find one lefthanded batsman in a cricket team, and a lot of advantage accruing to a left-arm bowler, but nowadays it is common to see two of both and even an ambidexter (bowl with one, bat with the other) at professional level. 

In my undergraduate days we mapped lefthandedness of our cohort against an intuitive spectrum with mathematics on the left, passing through theoretical physics via chemistry, engineering, geography.....towards history on the right. There was a remarkable correlation with over 25% of maths students  and fewer  than 10% of historians  being lefthanded, at a time when the national average was 10%.