In 1899, Einstein gave the following advice to Julia Niggli, a young woman acquaintance from Aarau who was agonizing over her possible marriage to an older man:
What a strange thing must be a girls soul! Do you really believe that you could find permanent happiness through others, even if this be the one and only beloved man? I know this sort of animal personally, from my own experience as I am one of them myself. Not too much should be expected from them, this I know quite exactly. Today we are sullen, tomorrow high-spirited, after tomorrow cold, then again irritated and half-sick of lifeand so it goesbut I have almost forgotten the unfaithfulness and ingratitude and selfishness, things in which almost all of us do significantly better than the good girls.
Einstein was 20 years old at the time and. to my mind, showed a surprising measure of self-awareness.
Oh, Mileva, take heed.