why

Well there is one thing i have learned over the yrs is that you can lie about a dog all you want, but a dog will tell on its owner everytime.
but on the other hand, i have seen some pretty good dogs that would look like crap if you took them around strange dogs and/or people. like was stated earlier a dog will make a lier out of you everytime, at least mine have, so i have learned to never bragg on my dogs ability, and that dogs are not robots, they will act differently in different situations, they do have a mind of their own.
As far as why do people talk trash, and beef up their dogs that aint worth a crap? well i guess its just wishful thinking and alot of jealousy.