Avraham Avinu was told to have a Bris at 99 years of age. Why didn't Hashem have him do a Bris earlier?
How old were Avraham Avinu and Sarah Imeinu when they got married?
What was Zimri's age at the time he had relations with Kozbi?
How old do you have to be to learn Kabbalah? (I think its 60 ) but it seems everyone learns it anyway (Maharal, Chassidus). Is there a defense or is it just done?
At which age should children be trained not to listen to music during sefira.