Well it all depends on the breed. Usually if it’s a smaller breed they tend to get out of the silly mood quicker then large breeds, but it also depends on the individual dog. I mean Foxy is three and he is still pretty silly. And don’t say to yourself “I cant wait for him to stop being silly” because if you think that’s a problem at the moment as soon as he grows out of it he will create something else. And not only that enjoy it while you can because it only happens once.