Oh, the irony.
Anyhow, here's something for everyone to consider, and this happened after the fall of man:
Ezekiel chapter 16
[1] Again the word of the LORD came unto me, saying,
[2] Son of man, cause Jerusalem to know her abominations,
[3] And say, Thus saith the Lord GOD unto Jerusalem; Thy birth and thy nativity is of the land of Canaan; thy father was an Amorite, and thy mother an Hittite.
[4] And as for thy nativity, in the day thou wast born thy navel was not cut, neither wast thou washed in water to supple thee; thou wast not salted at all, nor swaddled at all.
[5] None eye pitied thee, to do any of these unto thee, to have compassion upon thee; but thou wast cast out in the open field, to the lothing of thy person, in the day that thou wast born.
[6] And when I passed by thee, and saw thee polluted in thine own blood, I said unto thee when thou wast in thy blood, Live; yea, I said unto thee when thou wast in thy blood, Live.
[7] I have caused thee to multiply as the bud of the field, and thou hast increased and waxen great, and thou art come to excellent ornaments: thy breasts are fashioned, and thine hair is grown, whereas thou wast naked and bare.
[8] Now when I passed by thee, and looked upon thee, behold, thy time was the time of love; and I spread my skirt over thee, and covered thy nakedness: yea, I sware unto thee, and entered into a covenant with thee, saith the Lord GOD, and thou becamest mine.
Here, God likened his covenant with the nation of Israel to a marriage covenant, even as he does all throughout scripture.
When did God, figuratively speaking, see Israel as being fit for marriage?
Well, some of the indicators are "thy breasts are fashioned, and thine hair is grown", and these are both signs of puberty. It seems to me that God likened this timeframe to Israel's "time of love", and that is when he "spread his skirt over her", figuratively speaking, "and entered into a covenant with her".
Anyhow, there are plenty of indicators, from both scripture and recorded history, that younger men and women were a lot more mature back then than they presently are because of different factors.