Toilet paper, use it how you want, but everyone has to use it at one point, and when used under normal circumstances, is usually on a horizontal axis, within this orientation the paper is only able to have two permutations. The paper could either hang in front of (over) or behind of (under) the roll. While this is seemingly an unimportant topic and something that is left entirely up to opinion, or something that is simply dictated upon habit.

Although it has been taken as far
as considering age, sex, political and socioeconomic positions, for me it comes down to certain things that people seem to not understand, placing the paper over has its clear benefits, it reduces your risk of unnecessary contact with the wall or cabinet on which the paper is mounted, potentially preventing you from transferring the grime and germs that reside on the surface. Over makes it also easier to grasp the loose end of the paper, lessening minor inconveniences. Over allows services such as hotels, cruise ships, office buildings, and other similar places to fold over the last sheet to show that it has been cleaned, giving the user a peace of mind that there will be less of a potential of major contaminants, the only real benefit to having the paper go over is having a reduced risk of the paper unrolling.

And beyond this the patent that was filed for toilet paper, pictures a roll of toilet paper in the over position, and although some may argue that the inventors intentions of how their product should be used are not always followed, plenty of products are not used to the creator's original intentions, and that is a fair point, but you also don’t eat a banana sideways unless you're looking for a road hazard, due to the clear weakening of the structural integrity of the banana . However general intuition and gut feeling also tells me that people aren’t going under on purpose they just haven't experienced the superiority of having the paper go over.

So unless you wish to have paper that has rubbed against the walls of your restroom, picking up all the grime and germs and then using it, do not place the paper over, save yourself the embarrassment of being with the 30% of uninformed toilet paper users, and just hang it up how you are supposed to.