Imagine it like that: you are in a train and per the rules of the railway company, nobody can run in the corridors aboard the trains. Your train passes by anoth

Imagine it like that: you are in a train and per the rules of the railway company, nobody can run in the corridors aboard the trains. Your train passes by another train where the same no-run rule applies. If you can't run and a person in the other train cannot run, how the two of you can see each other for only a brief moment before you are carried kilometers from each other? Well, the rules do not apply to the trains both of you are occupying. So, though the two of you are relatively static, the underlying infrastructure is moving in different directions with speeds which are unfeasible for the passengers. In my previous comment, me and the sandwich were sharing the brief moment of unity that was broken apart by the runaway trajectory of the dog which made reunification impossible.