Could the answer be frustrated? When it comes to a beautiful dog, they would be right up near the top...
I had an Australian Cattle Dog (aka Blue Heeler) She was in my opinion the smartest dog in the world. I learned one very important thing from her, never get a dog that is smarter than you are!
Could the answer be frustrated?
Only for the first two years or so. They are lovers, clowns, athletes, energetic, empathetic and hard to groom. My current guy's grandmother was named Super Noodle...that about sums it up.