Spend weeks skimming seventeen volumes of Mark Twain's letters for references to Darwin, Lamarck, evolution or social development. Collect all relevant references into a single file. Collate according to potential usefulness. Accidentally delete one or twenty of them. Copy them again. Feel confusion. Know that you had that one reference. Remember that it was right there. Right there.
Skim letters again for the phrase "unfortunate development." Picture where you were and what it was like when you wrote it down. Think: "It was overcast that day ... which was when I looked at Volume IV!" Skim Volume IV.
Put off starting Twain chapter for a month. Feel pure bliss when the Mark Twain Project launched this week. Search Mark Twain's letters for "Darwin," "Lamarck," "evolution" and "social development." Save relevant letters to "My Citations." Feel "Happiness!"