The other thing, of course, that holds boundless interest is me. According to Puppy I am made up of hands, feet and a face to lick. All else is superfluous. My hands are of most interest because often they are the provider of things that are edible, my fingers are not but it's always worth a try.
It seems to be an instinct that puppies recognize cheeks as supremely lickable because the second you put a puppy face to your cheek they lick like mad. Noses count too but the cheek and chin are the preferred location for puppy kisses. And boy do I love those kisses.