In the autumn of 2010, Jonathan McMahon would from time to time climb into his wetsuit, and take a dip in the Irish Sea. Six months after joining the Central Bank of Ireland as head of financial institutions, McMahon, 35, was in need of some perspective.

Swimming at Forty Foot, the deep seawater inlet on the outskirts of Dublin which features in the opening passage of James Joyce's Ulysses, he would venture out when the water got a little rough, bobbing about as the waves crashed over him.