When a puppy or young dog arrives to his new home there are a lot of "first times" . If used correctly the command, can save a lot of time and work for both the dog and his owner. The dog learns that his actions will result in a pleaseant or unpleasant response from his owner whom by nature the dog wishes to please. If he , by instinct, correctly uses the designated zones ( chosen by the owner) where it is permissable for him eat , sleep, relieve himself and play then dog training would be very pleaseant for both. Unfortunately this is not usually the case. Good habits have to be taught. If a dog is allowed to develop "bad" habits these will only have to be broken later and the dog will have to be taught good habits. It makes sense to teach the dog acceptable behaviour from the start, although it is always possible to retrain a dog who has already naturally developed a behaviour pattern that is unacceptable to the owner.
It is my experience that any "bad" behaviour by a dog can be corrected. However to undo the bad habit and reprogramme the dog with good habits it is imperative that the dog understands exactly what is expected of him. In order to be fair to the dog he must learn , without any ambiguity, what is acceptable and unacceptable behaviour. He will be happiest when he learns by consistent and non contradictory instruction. That , in my expert opinion, means that an obedience training course should be undertaken at the earliest opportunity.