There is a ancient tradition in Japan, apparently when you save someone's life then that person will serve you throughout his life but this tradition have lost his value due course of time, similary if you are saving someone's story then same molecule of ancient history flow through the veins of the story teller. 

If you have noticed then this happens all the time. someone is telling the story and suddenly during important talking someone's interrupt him like a BOOM. suppose your house help or maid interrupt with a plate full of samosa or a small cute baby enters the room suddenly all the attention moves toward the plate or cute baby with paying much attention to the story teller. suddenly every one forgets that the story teller has not made his point. 

Take other example of a person who is telling a joke suddenly a small enter the room and  fall by chance due to which all the subject attention moved towards that notty boy and suddenly someone phone rings every starts talking about other topic but no body notices the joke teller every one has forgotten that that main punch line was still to make.Only one man know the one is telling the joke. You must have noticed that once you start making some point or begin a joke then suddenly waiters enters the area and start taking orders then you again start by saying so i was saying that instead of all this joke makers or story letter will regret later whole night that he could not end his story or joke in one go. so this is where you enters like a hero and help him with this technique name as to give a helping tounge. you can understand that its difficult to start story all again and gain attention from every one once again. he will remember you for saving him, That will set you apart from rest of the group if you are going to help him. You are more fortunate if you protect the story of someone that can hire you,someone that can buy from you, promote you, Big winners have elephants memory they never forget so in this way they are rewarded by lending a helping tounge. 

so whenever a story is interrupted due to waiter or crying baby. let people order the food, love their kids and give them some time so as to gather along and tell storyteller to start all gain and even better to remember him with his last few words