tweet-marginal-cost-is-writing-new-card
https://mobile.twitter.com/andy_matuschak/status/1075487476674834432
"This leads to a very unintuitive feeling: it's… effectively free to memorize as many new cards as I can write? What? Which in turn means that for me, the real marginal cost is in the moment of writing a new card." ^marginal-cost-writing