I've noticed this too, I think it has something to do with the fact that the two hands are "mirrored" in a sense, and operations like opening/closing arms are i

I've noticed this too, I think it has something to do with the fact that the two hands are "mirrored" in a sense, and operations like opening/closing arms are identical except for mirroring. Who knows, maybe they're even encoded like this somewhere in the brain. After getting used to it it's not that hard to write mirrored text with the opposite hand. It's definitely a lot easier than doing it with the dominant one.