Here’s the experiential equivalent to last week’s 三つ子の魂百まで.
(suzume hyaku made odori wasurezu;
“The sparrow, until 100, doesn’t forget [its] dance”)
What you learn in your youth stays with you your whole life. Just as the sparrow maintains its leaping, playful-looking flight style from when it first learns to fly until its death, so do people never lose the customs of their youth, especially the pastimes they turn to for amusement.
雀 (suzume) is the common Eurasian tree sparrow. Like last week, 百 (hyaku) is a hundred, specifically a hundred years of age, metaphorically one’s whole life; in modern writing one would probably expect a particle between it and the preceding noun phrase, but none is used. まで (made) is still “until.” However, in this case we get a complete sentence: the noun 踊り (odori), “dance,” based on the verb odoru (“to dance”), and the verb 忘る (wasuru), “to forget.”
Wait, “wasuru”? Yes. In classical Japanese grammar there was the verb wasuru. A grammatical distinction was made between “making an effort to forget; forgetting on purpose” – and “forgetting naturally when you weren’t thinking about something.” The former meaning conjugates as a 四段活用 (yodan katsuyou) verb. The latter conjugates as a 下二段活用 (shimo nidan katsuyou) verb. And since the point of the saying is that the swallow doesn’t forget its dance even over the course of a hundred years, we turn to the latter behavior.
The imperfective (未然形, mizenkei) form in this case is wasure, to which is affixed the auxiliary verb ず (zu) in sentence-final form.
There seems to be some disagreement over whether this saying can be used for positive things. One source gives “My grandfather is still good at judo” as an example of mistaken usage; another gives “My grandmother is still good at handball” as an example of correct usage. Since the image invoked is so nice, for the time being I’m going to assume that it can be used to describe lasting positive habits as well as negative ones.
The word まで can be written with the kanji character 迄. The verbal ending can be alternatively written as 忘れぬ (wasurenu) instead of wasurezu, which technically puts it in 連体 (rentai, attributive or prenominal) form. However, closer to the modern era, the nu ending is simply an alternate negative ending and can be found at the end of set phrases such as this one.
This saying is first attested in a poetry collection called 毛吹草 (Kefukigusa), printed in 1645; this instance uses the nu ending rather than the zu ending. The nu form is also found in the Kyoto iroha karuta set.
(“Suzume hyaku made odori wasurezu to iu ka, ojiichan wa kyuujuusai ni natte mo mainichi shichiji ni okite rajio taisou shiteru.”)
[“Like the sparrow doesn’t forget its dance even at a hundred, so to speak, grampa gets up every morning at seven to do radio calisthenics.”]