He came to us fully formed, a man. There were no weird childhood moments or awkward teenage years with Bruce Willis. By the time he was introduced to us on TV’s “Moonlighting,” he was already 30 years old, with a quarter-to-six o’clock shadow on his face and a mischievous glimmer in his eye, and a look like he’d been out having too much fun the night before. He’s been a steady presence on our screens ever since. Never a chameleon, always Bruce Willis, usually bald or balding, with a gruff charm and a sort of bleak resignation to the world. There is rarely an innocence with him. He’s always loo…