I know exactly what you mean. When I first got Jake, I would put him in my messenger bag and take him into the store with me because he could hide under the flap. He thought it was big fun and would lay so quietly in there in my bag in the child seat part of the cart while I pushed it and him around the store with only his little black nose sticking out.
Now... not even his head will fit in the bag. He's just 6 1/2 months old!!!! Went to the vet and he's 64 pounds!!!!!!! Where did my puppy go???
I can almost understand now why people get little dogs... almost.
Last night, he had a really bad dream and woke up mid bark. He got up and layed down, spoon fashion, in front of me so I could hug him and tell him it was okay. He doesn't fit in the crook of my arm any longer... he is the length of my torso and 1/3 down my legs. Almost like spooning another adult!!! LOL