Yes. I believe it's because I have better form with my left arm because
I think about it more than lifting with my right arm. It seems natural curling with my right arm but it's probably just bad form I picked up when I started lifting.
When I was younger I experienced this issue, it was because I would use my dominant hand to pick things up and place them on my non dominant hand. We had a couple of wood fire places that we used to heat our house in the winter (I live in Canada and it gets kinda cold up here sometimes), so I constantly would use my dominant hand to pick up fire wood and place it my non dominant arm. It sure lead to a nice looking left bicep and anterior delt. But when I began bodybuilding and utilizing more dumbbells they evened out, and yes I was kinda self concious about it and there still are some small differences but I think that they are more genetic than anything else.
my left is bigger, right was stronger and tried to compensate by throwing in an extra set on my left for a few weeks.. not sure if that was it, or trying to do curls and stuff soon after my shoulder dislocation (was my right, and it was weaker because of it)..
I also wonder that the left one responded to exercise more because it was weaker..