Sign up now! Sign up now! Sign up now? Sign up now! As rallying cries for the dawn of a golden era go, “I am quite optimistic” is not “ask not what your country can do for you, ask what you can do for your country”. It did not fit the “I think I am a special one” template set 22 years ago by Netflix’s latest documentary subject . Nor did Matthias Jaissle’s unveiling as Newcastle manager meet the pre-match billing of “fire” and “a rock star” that the club’s chief suit had promised the journalist…