I used to always keep it on the outside because I carried my crop on the inside and it just annoyed me to have them both on the same side lol. Now I usually keep it on the left because I mostly keep my crop in my right hand.
It's usually on the opposite side of my crop, and the crop is on whichever side needs it. If I flip my crop to the other hand, I may or may not flip the bight depending on how much trouble/busy that is.
Always, always on the left for me. I don't remember being taught that, either. I don't seem to notice the bight when it's on the left, but when it flips over on the right, it SURE bothers me for some reason. So weird.