I believe its If you get them when they are 15 or 16 they will pick your ducks, if you wait til they are 20 they will pick your pockets.
Two of my long time friends married women over 20 YO, both educated. Both had apparently happy marriages until their wives divorced and stripped them. Both wives had been laying their plans for years, one for the entire 17 years of the marriage (17 years is the time required d before an ex wife can get alimony in Florida). Both of the guys had become affluent, Klaus was a jewelry entrepreneur and Art a successful attorney. Each woke up one morning to find that they owned nothing and their wives were kicking them out of the wives' houses.
A third friend (of 50 years) married a 17 YO who had a 9th grade education. He prospered and she made herself into a model housewife that facilitated his ability to prosper. She also educated herself with his encouragement and when their 4 kids were grown she went to work (she doesn't call it work- she loves it)as an office manager in a college where she became the informal editor and collator for several professors' publishings. They are a very contented old couple.
Outside of the immediate subject-> They show that there is much more contentment in old age when one is surrounded by a bunch of grandchildren than when there are only one or two or none.
As for myself, I didn't marry until I was 23 but I had been "courting" my wife more or less since she was 13, 12 actually, but she totally shocked me when she announced it was her birthday. I expected to hear she was now maybe 16 or 17. It was her 13th. The first few years of that time I saw her at her family events and gatherings and ate dinner at her folks' house often, when I was in town. We both of us always kind of knew how it would turn out eventually, I think. It has been good. We do have a bunch of grandchildren but, alas, they are scattered about the world.