Showtime has dropped the first full trailer for its new half-hour comedy Happyish ahead of its April 26 premiere. Steve Coogan stars as Thom Payne, a 44-year-old whose world is thrown into disarray when his 25-year-old wunderkind boss arrives, saying things like "digital," "social" and "viral." Is he in need of a "rebranding," or does he just have a "low joy ceiling?" Check out the trailer above in which we see the troubled Payne mulling the idea of happiness with…