He who wants to educate himself in Chess must evade what is dead in Chess... the habit of playing with inferior opponents; the custom of avoiding difficult tasks; the weakness of uncritically taking over variations or rules discovered by others; the vanity which is self-sufficient; the incapacity for admitting mistakes; in brief, everything that leads to standstill or to anarchy.

p. 338 - Lasker's Manual of Chess (1925)