I am not sure whether it is actually an old wives' tale. Anyway I would call it that, as older ladies in Korea including my mother always said that babies reach next huge milestone after they overcome one illness. What seems to be quite true, is they just don't look the same once they fight off an illness. In our case, Jakob started to pump out so many new words after he suffered a bad fever for a few days. He had a tough three days fighting with a fever and swollen throat. He couldn't eat or sleep properly. Although he doesn't seem fully recovered, here is our little one that survived a 39.5 degree fever and is now saying many more new words.