Being a parent gets harder the older you are, not just becoming a parent which is where the focus tends to be. Yes you have fewer financial resources and less life experience, but if you want kids the best time is as soon as you can. Kids don't care about how rich you are (so long as needs are met - those concerns come later and enough will never be enough for a teenager) and they don't know that we're all making it up as you go along. Have kids at 25 means that by your early 40s you are pretty much free again but parented in times of good health.

Doing the school run now and seeing parents pushing 50 with primary school aged children makes me sad for them and their kids when I see how physically shattered they look through the fatigue and stress.