Ask anyone who owns a German shepherd dog and they will gladly tell you of the meaningful relationship they have with him or her. There is a consistent reason why all police dogs are of the GS breed. They give so much of themselves to humans, given the right upbringing
German shepherds are among the finest of dog breeds, loyal, intelligent, good natured and hard working. A GS in the family is a good choice but you must be prepared to lay solid foundations while they are still in puppy stage.
Training your puppy is crucial to a good quality of life for you and your dog. As a highly instinctive breed, German shepherds can revert to their feral roots if the rules are not bred into them from and early age.
The dog species in general, is a pack animal with a pack mentality. With no discipline your German shepherd puppy will begin to assert its alpha male pack leader mentality upon you and as he or she grows bigger, stronger and more confident, it will be harder to take his place as alpha male. A full grown German shepherd with total dominance is quite a scary scenario.
GS puppies are not mentally or emotionally matured till quite late, around three years but by this time they are already fully grown. A full grown GS puppy is easily capable of knocking a child or old person to the floor and while they mean no harm, it is potentially dangerous to be on the receiving end of one.
Lastly, dogs are social animals, they mix well with people and other dogs and as long as they have been trained and brought up to be well behaved, you will not have problems. However, keeping your puppy away from the world will cause complications when they do occasionally meet other dogs and people. They will look upon others with wariness and aggression, since they have no other way of viewing the situation.