It really depends. After going on a month-long trip, Google was serving me ads in German, as well as offering Google Photos printing expecting a German address

It really depends. After going on a month-long trip, Google was serving me ads in German, as well as offering Google Photos printing expecting a German address with the price in Euros, all despite us never entering Germany, let alone staying there long enough for it to assume permanent residence. This continued for about 6 months after.