how about the imprinting period or whatever you would call it, the age where puppies more or less soak up knowledge, and how the effect of how the dog is treated in this period, geting maximum out of it, or in worst cases teaching it many bad behaviors or expose it too bad situations making it very fearfull and nervous
the period is important because how you behave in this curiousity age where they so easily soak up new knowledge can be a massive tool in helping shaping them into good citizens or starting off on the wrong foot