Agreed, however if you are smart and honest with yourself and each other, and you both know what you want out of life, you can forgo the years of life experience and get married younger and grow up together. Worked for me, it's been fun.
It amazes me how some people even get to the point of engagement without first going down the checklist of life goals and values with each other. I have friends where one lives to ski (was on the US team even) and the other one never skied until she met him. And she wanted 4 kids (and now has them) and he wanted 2. They live very separate lives in the winter. Another friend I used to see all the time on the slopes is now basically gone from skiing because his wife refuses to ski, and they spend all their money on her horses now. Another was a skier and an Eagle Scout, very outdoorsy, she was a city-dweller and not very active due to a back injury.