When I left my mission I had an interview with my mission president, as all returning missionaries do I believe. He asked me if there was someone special waiting for me at home. I told him not really, but there were a few prospects. He said that it is our duty to multiply and replenish the earth. He said our sacred responsibility was to bring many children directly into the fold born "under the covenant". He told me not to wait, but to immediately start looking for my eternal mate and to begin our family as soon as heavenly father directed her to me (his words).
I then had an interview with a member of the area presidency. They were on-hand as I was one of the first groups of missionaries moved to East Germany to finish out my mission (spent my last year there), and me and another Elder were among the first to leave the mission that was just newly re-opened a year and a half before or so. The area authority, I cannot remember who he was, probably in my journals somewhere, gave me almost exactly the same spiel as my mission president had. That our sacred responsibility was to find our eternal mate, be sealed in the temple and bring children into the fold, so as many of God's children as possible were "born under the convenant". He also said to get married as soon as heavenly father directed my future wife to me, and not to make the mistake, that often leads to grave sin (his words), of waiting and prolonging any relationship that was not blessed in the temple.
Needless to say, when I got home I felt bad taking some girls out when it was just for fun and I didn't view them as marriage material. I really dated only a couple of girls before asking one to marry me. Luckily we have made it work, and have been married almost 23 years now, with 3 great kids, and another kid. But I still feel like a lot of that was a big mistake and I have often wondered how my life would have turned out differently had I waited and gotten my bearings after my mission before being worried about settling down.
Do not get me wrong, I do not in any way blame those church leaders for a "life gone wrong" or any such crap, but I do wonder how much differently things would have been if I had waited, and waited to have kids, until I (and she) was more emotionally and financially prepared to handle it. I also wonder if I would have started to wonder, sorry if that sounds weird. What is interesting is my mission president tried to drive the point home about getting married quickly by telling me that regret is the most destructive force in the universe and something to be avoided, so to get married soon so I don't regret it. When in actuality I have at time regretted marrying and having kids so soon (by no stretch the who part, just the timing).
I believe the whole idea of multiply and replenish the earth was pushed much harder in earlier years of the church. When I talked to my dad about this one time, he told me he could remember as a very young bishop (in the 1960's and in his early 30's) that they should push very hard to get their young kids married in the temple so they could avoid a life of sin. He was admonished for not pushing young kids hard enough to get married if they chose not to go on a mission. He told me they were pushed harder about marrying as soon as possible than they ever were about serving a mission.