Puppies definitely need a lot of work. We were prepared for that from our research, but good God....... 
It seems like Belle (our golden) changed instantaneously at about 1 year old and again at about 2 years old. She's the sweetest critter you can imagine. Dumb as a box of rocks, but sweet.....
I had a dog, a Golden Mix once. Moose. Dumb as a friggin stump, but a heart of gold.

I work with our local rescue groups here, and see way too many dogs abandoned because of the work involved. It is a sad but undeniable truth.