I was thinking about what I didn't know about kids until I had them. When you think you want babies, you really should look at whether you want to be a parent to a helpless baby who turns really quickly into a toddler, who instantly morphs into a grade-school child, who then breezes through the teenage years and all-of-a-sudden-oh-my-gosh that teenager drives away to college and you look in the mirror and realize you did your best!
Your life is never the same after that baby enters your life, and you should really be asking yourself if you think you can be selfless for 22 years. I am glad I did and was, but what a whirlwind! Still, I wouldn't change it for anything.