it also has an option to save your wifi details to the cloud, which must have been set.
I got a new apple watch recently and all i had to do was pair it to my phone and then place the old watch beside the new one. Within 30 seconds it was up and running with all the same apps as the old watch
Another neat update i saw recently was the one of my cards was due to expire on apple pay and the bank sent an update to my phone/watch with the new card detail automatically. Gone are the days of having to input new card details