Belichick Has Happy Press Conferences?
NO. However, I did find several seconds of video footage from one that proves that they're not all angry and awkward.
While researching their upcoming opponent, Buffalo, I stumbled across this remarkable footage from the NFL's Official YouTube channel.
Usually after The Pats sew up a first round bye in the AFC Playoff Picture, there is a three day window in which he is almost happy. ALMOST.
Be on the lookout for this type of behavior around Christmas but do NOT mistake it for Holiday cheer.