So I become rightfully engraged when my peace is ruined by triviality: a knock on the door, for example, or a phone call. The good thing is I live in a townhouse where it is rare to receive knocks and, when it happens, it is already an expected welcome event (my niece delivering pasalubong from their family's most recent outing).
An unannounced phone call, on the other hand, is an emergency in my vocabulary. You are calling because an urgent response is crucial. Thus my anxiety. What could be wrong at this moment?
So I become rightfully engraged when someone suddenly calls for reasons less important than life-and-death: to yap, to sell, to send emailable information. I say, How dare you decide that I will spare time for you; that I will drop everything to answer, actively listen, and manage emotions? No, ask persmission, allow me to prepare, text first.