[LunarBerry]

Oh yea, the baby times She'll grow up so fast that you'll almost literally miss it if you blink. Though I'm glad my furbaby is out of the baby-baby stage (less stress over her safety for every single little thing), I sometimes miss her cute little fluffy, playful, pudginess ^_^ Granted.. she hadn't changed much except get bigger lol :P
Once they get around a year or two old they start to mellow a touch and get into routine better, depending on how active they stay and the training/routine they are given. Of course that varies on the yorkie, too.