In recent years I’ve seen a lot of speculation that Christie had ADHD—I don’t know what the evidence is supposed to be though I wouldn’t be surprised – certainly some of her characters (frex Lady Angkatell in The Hollow) seem to, and they’re described vividly and often from the inside out, as it were. But from her memoirs, her older brother *definitely* did, and I think perhaps her mother as well. Christie was apparently considered “the slow one” in her family, and it wasn’t until she grew up and began meeting more people that she realized this was an extremely relative term.