you realize this once you keep seeing the same travellers over and over again.
our first day in Hoi An, we ran into the irish lads we were hanging out with a couple night before from Hue. (and from the train from Hue.) this of course resulted in another night of late drinking.
we then ran into a british couple who we met on the train from Hanoi up to Lao Cai. (on our way to sapa.)
we then saw another girl we had met at a resturant while up in sapa.
finally, we recoginezed another girl who had gotten really upset and caused a scene in the lobby of our hotel in Hanoi.
all the travellers in this country are either heading north or south, and if they're heading in the same direction as you, it seems you constantly run into them again and again. it's feels a little weird when you get into a new town and start wandering around only to see faces that look remotely familiar.