you're never too old to learn

the sixteenth night of the month under the lunar calendar, just after the full moon

Short for 十六夜の月 (izayoi no tsuki): the moon just past the full moon, the start of the waning moon

one, 1 / the first in order, foremost / the beginning / the best / a kind of; one of something / (card games) an ace / unity / the bottom string of a shamisen or other Japanese musical instrument

a hendecagon

eleventh day of the month

thirty-one; 31

forty-one; 41

eleven o'clock

twenty-one; 21