If you ever owned a dog when you were a child, you can probably recall the joy and exhilaration you felt every day, playing with your best buddy. Once you grew up and (assuming you) started a family, you probably wanted your kid(s) to experience the same things that you did. A loving, loyal, fun-loving animal companion is one of the best things in the world.
For the health and wellbeing of your dog, training should really not ever be considered an option when owning a dog. Well trained dogs are more likely to be behaved and listen, be void of behavioral issues, be good in public, and are less likely to bite. Owners also have a much closer connection with the dog when the time is taken to form a relationship through training.
All dogs need to be exercised everyday in some form or fashion. The most common method is through the walk around the neighborhood, but is a short walk around the block enough exercise for your particular dog?