There is a show on cable television, perhaps you have seen it, which chronicles the misadventures of rude airline passengers when things go wrong. The show is interesting because it clearly demonstrates the connection between bad behavior and bad outcomes. This well-known and even scientific principle of “Cause and Effect” is known as 'Karma' in Buddhism. When we apply the law of “Cause and Effect” to the scenario of the typical stranded airline passenger, we can clearly discern the wisdom of learning to control our thoughts.
Let’s say there is an airline passenger who has missed his connecting flight, through no fault of his own. By observing the the principles of Cause and Effect, we can track the relationship between thought and results. In this scenario, this passenger who has missed his flight allows himself to indulge the thought that, “This airline has made me miss my connecting flight—it’s their fault.” (Notice the externalization of his problem). This accusatory thought feeds his angry feelings towards the airline. Proceeding in this state of mind (and emotion) to the ticketing counter to try and get another flight out, his angry vibe puts the ticketing agent on the defensive—who is thus disinclined to exert any special effort to help this loud jerk. Result? An unanticipated night in a hotel, at the expense of the airline. Note the “Cause and Effect” relationship between his thoughts and his results.
Now lets take the same scenario from a different perspective. Instead of allowing his mind to indulge an accusation towards the airline, this passenger now sees the situation clearly—this situation is simply beyond his control. Now his thoughts are not feeding his anger— he is calm. Proceeding to the ticketing counter, he engages the agent in a pleasant way, who is thus now inclined to feel sorry for him, and exert an extra effort to help him. Result? Amazingly, a seat on a flight out has just come open. No extra night in the airport hotel.
Obviously, life does not always work out this way, but the lesson is clear enough: learning to control our thoughts can affect our lives in a positive way.