Two things: a. underestimating 'compound interest' (if I may say so) of repetitions from past material you must do in the future. As more and more material is d

Two things: a. underestimating 'compound interest' (if I may say so) of repetitions from past material you must do in the future. As more and more material is done, there are more repetitions you must do every day, simply because you're forgetting some of the material. So simple '20k / X new words per day' gives BIG error. b. "I had multiple one day slips" is another one, especially as you quickly "learn" that the more new ones you do, bigger daily repetitions number follows :) So quite often I was just doing repetitions to reduce burden on me. Guessing from my memory, average repetition number over that 10y would be around 100 per day. BTW: You can start with smaller db. e.g. I started in the middle doing Russian one and used a 5k one.