I think it depends on the person though, there are those who should wait and there are those who would be ready at a young age.
My parents were young 22 and 20 when they were married. They had me two years later... they divorced two years after that... They liked to party though.
Where as I am more reserved. I don't like to party. So getting married young wouldn't be so much a hassle. Thing is ... you could be older, be ready to marry and things STILL not work out well...