Talos is 15 weeks old - his socialization window is closing as I type this. Socialization window? What the heck is that?
We've spent the past six weeks or so introducing Talos to new things (places, people, sights, sounds, surfaces, dogs, experiences) so he won't find those things scary later in life.
Dogs who don't "see the world" in their first 12 - 16 weeks can be severely handicapped (socially) as they mature. Many undersocialized dogs develop fear, anxiety, and phobias, when not properly exposed to the sights and sounds of the world.
Many of my clients have fearful dogs. Fearful dogs who would rather bite someone (or some dog) than make friends. They bite because they're scared, not because they're bad or mean.
It's your responsibility as a dog owner to get that puppy out there and expose him (safely!) to the world around him. You can't accomplish this by taking your dog to obedience class once a week. You need to take your dog out every day to a new location so he can see new sights, new people, have new experiences.
It's not good enough that he sees the same 10 people - he needs to experience new people every day. It's not good enough that he plays with the neighborhood dogs - he needs to meet new (friendly and appropriate!) dogs daily.
I've been able to get Talos out to new places every day, but was having a very difficult time finding him new doggie friends to meet. So we signed up for doggie daycare. In doggie daycare (a well-run one, at least) dogs are screened to ensure they're nice, appropriate dogs. (We think Coventry School for Dogs in Columbia, MD is fantastic, by the way. They group puppies according to play-styles, ensure that pups get enough rest, and aren't over stimulated. It's fantastic!)
I've noticed a marked improvement in Talos' doggie social skills since he's been going to daycare a few days a week. Before he started attending daycare, he'd freeze when other dogs would come near. Knowing that's a sign of fear/anxiety, and also knowing that Talos will weigh about 150 pounds as an adult, I knew I had work to do -- and it had to be done quickly! Believe me, you don't want a 150 pound fearful dog - the consequences could be dire.
Don't think you have time to socialize your dog? You don't have time NOT to socialize your dog. Spend a few hours each week now and you'll save yourself hundreds of hours (and hundreds [if you're lucky] of dollars) later trying to rehabilitate a fear-aggressive dog who won't let people into the house or who you can't take anywhere with you.