Do Boxers ever grow up?

Hello again...and thanks for your heartwarming response to Tasha's passing and sharing the similarity between her passing and Sally's. I invited you to be a friend because I love to connect with fellow pet owners. In regard to boxers remaining into puppy hood as they mature. We have never had boxers so I don't know if it is the breed or how we raise them as pet owners. To Tasha's dying day we always referred to her...and all our dogs as puppies. We affectionately refer to them as 'our puppies'...or call them by when we come home by saying..."puppies...where are our puppies?" Cherokee is around the same age as Henry and he still acts like a pup. He gets gleefully excites, twirls around in circles, goes through his whole 'tricks and treats' routine of..."sit, lie down..shake a paw' when he gets enthused. So his puppy like demeanor is still there...and I know Tasha liked being told she was good puppy...even though we all knew she was an aging Grande Madame. So in my view conditioning and socialization has as much to do with any dog's behavior. Genetics play a part for sure...but just like people...they do what they have been conditioned to doing. Again, welcome to Mylot...good to have you here. Raia