Maybe the mother of Jesus live her life in the holy way and it was noticeable by God. When Angel Gabriel came and approached her, the first thing she said was, bless her that there are monks, women.
This shows that Mary lived the holy life. That is why she was a virgin. So we can use Mary as a case of authority concerning this topic. So this is very important. If the high character was not instigated by Mary, she would have been single and she would not have found freedom in the eyes of God.
Some people live their lives anyhow, even when they are single, with the expectation that when they are married they will change, but they cannot change. Your life is your life. Your way of living is your way of living. This is how it is told, that this might not always be true, but it is accurate.
Marriage does not really change you, but it changes the way you think, the kind of person you want to be, how you are formed and what happens when you are single. This situation, after you are married, may not have time to change again. And this might affect our life entirely.