In this world, Christians (JWs) cannot isolate themselves from dealings with non-Christians (non-JWs) as it is necessary for our everyday functioning. However, yes, following Biblical admonishings, a true/serious JW does not have close/intimate association with non-JWs as there's nothing in common for such a relationship; our way of life is much too different for any significant relationship to solidify with a non-JW.
It's just the way it is.
DY