In January, Fine Gael TD Ciarán Cannon and his wife Niamh headed for Lanzarote armed with a bicycle each and an elephant in the room. Cannon, at 58, is two years younger than the age at which his father died. “I still miss him an awful lot,” he says from his office in government buildings. Last summer, one Wednesday evening, a letter arrived at the couple’s Co Galway home. “Niamh took a picture of the letter and sent it to me,” Cannon recalls. “It was horrific; it was horrific. It went at me first, then at her in great detail,…