Nobody seems to know (at least that I can find on the internet anyway) where this trend originated, which I think is awesome. Am always amazed and fascinated at these little traits that we humans have, what is that called? Anthropology?
I am not usually one to be soppy over love + relationships but this is one gesture that I really like.
Unfortunately, sometimes, relationships don't last forever, even when you are certain that they would or should. But in my experience any relationship you have, whether it is a long or a short one, that crazy stupid love that means you can't think straight or the kind that is similar to being hugged by that thing in that soup in a mug advert. They impact you, they change the way you think, they make you smile / frown / laugh / swear / reminisce at a memory, so I guess I like the permanent symbolism of this trending ritual. And I like that you can see how many people are in or have been in a relationship that means so much to them that they are willing to declare it on a padlock, lock that padlock to a permanent structure and throw away they key forever.