Large breed dogs take longer to mature physically into their adult size, which is a boon to anyone who loves the puppy years. As they grow, dogs may experience clumsy movements and struggle to adjust to their bodies as quickly as they would like, says the pet food company Canidae. It's comparable to the awkward teenage years that humans go through. Large breeds may not understand how big they are. As a result, they may try to sit on your lap or fit on a dog bed they have outgrown. Large breed adolescent dogs also may step on your feet and/or fail to understand their own strength as they jump up to offer kisses. Over time, large pups will reach physical and emotional maturity and have a better sense of self.