The fist number of L. refer to the standard CtP edition published in 1987. The following number shows correspondence between letters in the new 2010 edition. Note that on this website CtP is available only 1987 edition with minor additions.

[L. 34 | 41] 19 August 1964

You are right, life is not so very simple for anyone. And once one has got fixed habits and is accustomed to one's little self-indulgences, and perhaps made a certain position for oneself in the world (professional seniority, the regard of one's colleagues, and so on), it is not so easy to make a drastic change and take a leap into what is really something of an unknown element.