Experience is the best teacher. This is a trite phrase or axiom that we all subscribe to. So why do we try to stop people that are about ready to learn by experience that something is just not going to work out for them? When you have wisdom gained by experience it is very easy to reach your hand out and try to stop someone from making a mistake that you yourself made many times. However, when you do so, what have you accomplished really?
Most of the times you make an enemy, or create enmity between you and the person that you are trying to stop from making a mistake. If the mistake is not life threatening, then perhaps the best course of action is not to interrupt. After all, when some wise person tried to stop you, did you? No, you got mad at them and did what you were intending to do anyway.
A more important consideration. If someone is adversarial to you, or working against your purposes then by no means should you interrupt the course they are on. If you really believe that your course is correct, then you should absolutely let the other party proceed with their plan because it will fail. That is the strongest and most convincing argument that your path is correct, is when the alternative paths fail. As the Art of War says, never interrupt your enemy while they are making a mistake. Go ahead and let them happily plunge off the proverbial cliff.
Patience to see your plan through, and all other people’s plans to take their natural course is perhaps one of the most difficult things to do. However, it is absolutely wise and saves you a ton of stress. You are not going to be able to convince people they are wrong, for the same reasons they will not convince you that you are wrong, so just let it happen. Do not interrupt the greatest teacher working her magic. Let experience do her thing.