FWIW, this is the exact opposite of what my most important advice would be. Don't settle down in your 20s. Your life ends as soon as you have kids. You do get a new life, but it's radically different from the life you had, and not really yours.

Also, when you're 35, you will likely have a much better understanding of what really matters to you, and what kind of partner you really want for the long haul.

It's often said that "60 is the new 50" — and it is, if you do it right — the corollary is something like, "25 is the new 19". That's a gift! Take advantage.