Chinese sage Confucius famously said this about his own life:
– When I was fifteen, I was determined in my studies.
– At thirty, I was self-established.
– At forty, I could no longer be confused nor tempted.
– At fifty, I understood my divine destiny.
– At sixty, I was undisturbed by anything I hear (ie, opposing views).
– At seventy, I could do whatever I wish and still stay within moral and ethical bounds.

(Original text: “吾十有五而志于学,三十而立,四十而不惑,五十而知天命,六十而耳顺,七十而从心所欲不踰矩。”)

As I turn forty, I realized that not being a sage myself, I’ve miss every one of his development milestones.

I didn’t learn Dharma at 15, I did so at age 20.  My delta with respect to Confucius was 5 years.

I didn’t become financially independent until 33, my delta was 3 years.

Having turned 40, I still can be confused and tempted.  Given my historical trajectory, I’m hoping the upper-bond of my next delta will be 3 years => I should reach that milestone no later than age 43.  I hope.