When you are exasperated by interruptions, try to remember that their very frequency may indicate the true value of your life. Only the people who are full of help and strength are burdened by other people's needs. The interruptions at which we chafe are the credentials of our indispensability.
The greatest condemnation which anyone could incur--and it is a danger to guard against--is to be so independent, so unhelpful, that nobody ever interrupts us and we are left comfortably alone.