The question of what month is hardest with a puppy cannot be directly answered as the text does not specify a particular month but rather a stage in the puppy's development. However, according to the provided text, the challenging period for dog training occurs during a puppy’s adolescent phase—generally from 6 to 18 months old. This phase is marked by hormonal changes, growing independence, and exuberant energy, making it particularly difficult for owners. Common challenges include regression in training, increased distractibility, stubborn behavior, and heightened energy and boredom. To navigate this stage effectively, owners can use strategies such as staying consistent, using positive reinforcement, engaging the mind, and managing the environment. Leveraging expert resources and continuing socialization are also crucial. Perhaps the most important message for pet owners is to remain patient, as training during adolescence can feel like starting over, but with consistency, compassion, and proper guidance, both dogs and owners emerge with a stronger bond. Recognizing the challenges allows expectations to be realistic and progress to feel more rewarding. Training a puppy through adolescence is undoubtedly challenging, but it’s also a pivotal time in their behavioral development.