There are some very strange sleep surveys out there and we managed to stumble upon one by Sealy mattress manufacturers that studied sleep position and likely careers (it also covered a bunch of other weird statistics). Apparently, those who sleep on their right side are more likely to work manual jobs, such as transport, logistics, and manufacturing. They're also more likely to smoke cigarettes and drink caffeinated beverages.
Are all right side sleepers chain smoking, coffee drinking train drivers? No, definitely not. The survey just showed results skewed in that direction. It is interesting to note, though, that those working physical jobs tend to sleep in a position that is generally considered physically better for your body. We wonder if there's any correlation. We're not scientists, but it certainly seems like a pretty big coincidence!