Training your dog may seem like plain common sense to some dog owners but there are far more untrained dogs than there are trained dogs. Whatever the case may be, whether it is a time commitment issue or just not knowing where to start, there is always a compromise that can be made in your schedule where you can start the training process. Being a responsible owner means teaching your dog at least the basic obedience commands. It is necessary to have a well behaved dog when going out into public areas for many reasons. A trained dog will not chase after cats or run into the street, he will not bark at strange dogs or human, he will be calm and not pull on his leash. Imagine being out in public with a wild child that doesn't listen and causes commotion. The same way you would raise your children to mind their manners, should you raise your dog to mind his.
Puppyhood is of course the best time to start training but if you have an older dog don't think that all hope is lost. The saying “You can't teach an old dog new tricks” is not true. I believe that saying stemmed from a person who lacked patience and commitment. If you understand how to train a dog and use the skills you have gained correctly, you should have no problem implemented a plan and seeing results. Even if your dog learns more slowly than you would wish, he is still learning.