Border Collies are often cited as incredibly bright animals, but just how bright are they? Renowned canine cognition expert Stanley Coren concluded the breed was smartest in his book, The Intelligence of Dogs, based on the dogs' ability to understand, fulfill and remember commands almost immediately 95% of the time. Other studies have shown that Border Collies, unlike other dog breeds, are able to develop vast "vocabularies"; one Border Collie from South Carolina once demonstrated that she knew over 1,000 English nouns. The dogs also know how to differentiate between objects with which they're familiar and objects they've never seen before. That's part of what makes Bieber -- the Border Collie in this video, not the famous pop star (and former monkey owner) -- so impressive: after hearing the name of a new toy just a few times, the dog clearly attaches word to object and knows how to pick it out from a group. And, studies suggest, he'll remember this new word the rest of his life.