I think it is TS  Elliot who said, 'Let me not hear of the wisdom of old men, but rather their folly".  Well in that case my dear Elliot , let me tell you about Herbert Henry Asquith, the last liberal PM of the UK and his final two years in office.  Or rather, let it be done by the doyen of modern historical fiction (we leave the all-time title in the safe hands of Sir Walter Scott), Robert Harris.  Harris tells the story of 58-year old Asquith's la liaison with 20-something, Ventia Stanley, through the 560 letters he wrote to her (mostly during WWI) and her imagined responses.  Yes, despite the folly of old men, he had the good sense to burn the letters he received from her on his last day in office.  The novel is obviously not a fast-paced riveting read, but more a warning about how the best-known folly of old men leads to obsession and errors of judgment often leading to a loss of legacy.  What Harris however did well, is to demonstrate Stanley's influence on UK politics through Asquith's almost childlike need for counsel from her.  Apart from that, the novel could have been a novella and is definitely not one of Harris' most accessible works.