The general believe that experience is the best teacher have always mislead people when making choices.
People tend to base their decisions on chance. No doubt we learn from experience but experiences were meant as a 'guide' and not an 'end'. Experience is a bad teacher because it does not allow for trial, it does not give you chance to repent in case of failure.
The mistakes of others should shape our decisions but we should never seek wisdom from it. Decisions should be properly thought over. Critical reasoning should be applied.
In as much as mistakes are bound to occur, wisdom should be your watch.