We often are told that people waited 6 months before they began looking to begin training their puppy because they were given advice to let their puppy enjoy life as a puppy, like a free spirit.
Um....I suggest you redirect that same analogy on human children and everyone would know exactly what you would get....a very disrespectful toddler, with established bad habits.
By beginning training early, you are not being mean. You are providing needed guidance to understand the rules in your home. Early dog training enables you to create a calm and balanced dog. The younger the puppy, the easier they are to train in the good habits, and to prevent the bad dog behavior from even occurring.
Training your puppy while young will take moments, rather than weeks. We can teach a puppy new things quickly and mold them into respectable house mates. Training is always on-going as your puppy grows, but the important stuff holds stronger and longer when you initiate early training with your dog.