Accidents are a part of our real life. It is possible to see an old friend accidentally. It is possible to find a fallen comet accidentally. It is possible to kill someone by an accident, etc. Many stories of our real life are based on an accident. Also many good "realistic" stories begin by occurrence of an accident for the main character. But based on my personal experience in the life I think occurrence of "two" independent accidents in a "single" drama is rare and strange. So it seems if I want to write a realistic story I should avoid occurrence of frequent accidents in it. In the other words it seems that a story which begins with an accident could be reasonably realistic even if this accident is too strange or rare to happen but a story with more than one accident seems unnatural and unrealistic.
Question: Does frequent occurrence of accidents in a single story harm its realistic content? As an example, can we be almost sure that a story which its main character accidentally sees his old friend in the street and also finds a comet in his garden in the same day, is not a story based on the truth? Do these stories produce a sense of being unrealistic for their audiences?