I don't necessarily feel this is gospel that applies to all dogs. Yes, to some, but how do you explain rescues that are locked in cages for years, adopted out with someone who takes the time to enable them to gain confidence and then they bloom into this great dog? On the other hand, there are rescues that never blossom. There are pups, well socialized during that exact time frame - some are great, some are not. I guess, my point is, I don't feel all is lost outside that 12 weeks and I sure as heck wonder who thought it up! Think on it.... how much socialization truly does happen prior to 12 weeks when pup is not fully vaccinated? It may set a stage, or help push dog owners to act, but I don't feel it is as cut and dry.
Deacon is 21 weeks - same age as Blueberry. He has actually been paws on the ground longer than Blueberry who had to wait for her titers. Both pups have been with other dogs in the home, with owners working on socializing. Blueberry is leaps and bounds ahead of Deacon who is just now coming into his own confidence with different things. If that window was closed at 12 weeks, I'd have a pup afraid to go on walks and Blueberry surely would be a lost cause waiting for her titer results. Instead, Blueberry has a more confident personality to begin with so she is meeting life head on with each activity she is introduced to. Deacon is a 'let me wait at the door and watch for a while before I decide if I want to enter the room' type but he's getting better.
Deacon lives with 2 pups who he races around with, herds and terrorizes at home, came from a litter of 5, we have dogs all around us, he went to puppy school - he does NOT like other dogs big or small. I'm not giving up because he is past that 12 week time frame - I'm just taking it slow. Introducing things in HIS time frame, not mine. Deacon is a loving, soft hearted wanna be lap dog - he's not some high energy, super confident, out going, ball of fur rolling around everywhere. He's getting better, he's just slower at attaining confidence in things.
Point is - socializing and training is a life long thing. I know with Brodie, we did all according to the experts - he went through a fear stage at about 16 months where we literally had to start from the beginning. His door wasn't closed at 12 weeks either. Maybe it's sort of like vaccinations.... we know from titers that vaccines provide more immunity to our dogs than just a year, yet many are convinced they MUST be vaccinated annually, hence they bring their dog to the vet for an annual check up which IS super, super important and many folks would brush off to save money. Maybe the folks preaching that train of thought are doing the same thing - saying something to give a sense of urgency to those who might not act in any way otherwise unless they feel it is some vital threshold they MUST pass over or face having a wild animal in their home instead of a well behaved dog. Who knows...
As it could have been anyone including you, though not me as I don't know what was in the post even. 
