what if they get attracted to someone else after sometime and they realize that what they felt at very young age was not love it was just infatuation?  

Instead of going through all the hassles of divorcee, its better to get married when they are emotionally more matured say between 24 to 28 for men and 22 to 25 for girls.

You said you are single...is that because you never felt the urge for a gf?