One time after clearing out a Stormcloak camp, my horse was nowhere to be seen, so I just got on one of the Stormcloaks' horses. Since the Stormcloaks were dead, the horse wasn't 'owned', so riding it didn't count as stealing (because, of course, it's perfectly fine to take people's stuff *after* you've killed them ), but neither did I acquire the horse (i.e., it wasn't marked as 'Ytheria's horse'). The expected behaviour was that the new horse would wander off after I finished riding it, and then when I fast-travelled, my own horse would reappear.

However, the actual behaviour is that whenever I fast travel, the new horse reappears. It always wanders off if left on its own, so I need to mount it pretty sharpish if I want to ride, and I can never find it in stables, but whenever I fast travel, it comes back. Moreover, I've just discovered that this is true *even if the horse died*. Recently, I encountered a random dragon, dragon torched horse, I killed dragon, fast-travelled back to Honeyside to dump the bones, fast-travelled back again to continue my journey, mounted my horse ... and then the corpse of the same horse fell down the mountain in front of me.

Does this happen to other people?

Didnt know that it would follow me even after death but Yes I did wonder why I kept running into the same horse all over Skyrim.