'I am out of step with present conditions. When the game is no longer played your way, it is only human to say the new approach is all wrong, bound to lead to trouble, and so on. On one point, however, I am clear. I will not abandon a previous approach whose logic I understand ( although I find it difficult to apply ) even though it may mean foregoing large, and apparently easy, profits to embrace an approach which I don't fully understand, have not practiced successfully, and which possibly could lead to substantial permanent loss of capital.' - in a letter to his partners in the stock market frenzy of 1969.