Most successes are unhappy. That's why they are successes - they have to reassure themselves about themselves by achieving something that the world will notice.
The popular idea that a child forgets easily is not an accurate one. Many people go right through life in the grip of an idea which has been impressed on them in very tender years.
Too much mercy... often resulted in further crimes which were fatal to innocent victims who need not have been victims if justice had been put first and mercy second.