What does the Bible say about adulthood

Now Abraham and Sarah were old and well stricken in age; and it ceased to be with Sarah after the manner of women. KJV...

And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age. KJV...

For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him. KJV...

And she said, Who would have said unto Abraham, that Sarah should have given children suck? for I have born him a son in his old age. KJV...

And Abraham was old, and well stricken in age: and the LORD had blessed Abraham in all things. KJV...

Then Abraham gave up the ghost, and died in a good old age, an old man, and full of years; and was gathered to his people. KJV...

Now Israel loved Joseph more than all his children, because he was the son of his old age: and he made him a coat of many colors. KJV...

And we said unto my lord, We have a father, an old man, and a child of his old age, a little one; and his brother is dead, and he alone is left of his mother, and his father loveth him. KJV...

Now the eyes of Israel were dim for age, so that he could not see. And he brought them near unto him; and he kissed them, and embraced them. KJV...