The Rambam writes (Hilchas Ishus Perek 15 Halacha 2), a man should get married at the age of 17. The Magid Mishnah asks from the Mishnah In Avos that says, "Ben Shmoneh Esreh LiChupah" - a man should get married at the age of 18? How can the Rambam write 17? The Magid Mishnah anwers, when the Mishnah says that one should get marries at 18, it means in the 18th year of his life...,which is after his 17th birthday. The Mishnah is therefore saying the same as the Rambam.
Sefer Gan Raveh brings a proof to the opinion of the Rambam. The pasuk in Parshas VaYigash lists the 10 sons of Binyamin. One of his sons was called Chupim. Targum Yonason Ben Uziel explains, all the names of Binyamin's sons were named after an episode that connected to his brother Yosef. He named his son Chupim - because Yosef was sold at the time that he was fit for Chuppah - fit to get married. We know, in Parshas VaYeishev the pasuk clearly states that Yosef was sold at the age of 17 ("Yosef Ben Shva Esreh Shana"). How then can Yonason Ben Uziel say that Yosef was at the age of marriage when he was sold? It must be that Yonason Ben Uziel agrees with the Rambam that "Ben Shmoneh Esreh LiChupah" means at the age of 17... in the 18th year!
Rabbi Ben Tzion Shafier discusses marriage and divorce at Mishpacha Magazine.
“We’re seeing significantly more divorces today than in previous years, and I attribute it to three reasons. Firstly, people are more fragile today; they lack a certain ‘wholesomeness,’ a sense of being comfortable with who they are and where they fit in the world.
He cites the “age of consumerism” as the second biggest factor in many divorces today, the premise of which is that there’s always a better, newer model out there.
Read more: http://www.mishpacha.com/Browse/Article/3679/The-Before-and-After-of-Great-Marriages