Napoleon excelled at mathematics. ‘To be a good general you must know mathematics,’ he later observed, ‘it serves to direct your thinking in a thousand circumstances.’ He was helped by his prodigious memory. ‘A singular thing about me is my memory,’ he once boasted. ‘As a boy I knew the logarithms of thirty or forty numbers.’ Napoleon was given permission to take maths classes earlier than the prescribed age of twelve, and soon mastered geometry, algebra and trigonometry.

Napoleon: A Life, p. 11

However, he did have one flaw:

[His mistress Giuseppina] Grassini complained that Napoleon’s ‘caresses were on the furtive side’, and often left her unsatisfied, and in this she wasn’t alone. He never took time over his lovemaking, once reporting to an aide, ‘The matter was over in three minutes.’

Napoleon: A Life, p. 269