They pretty much figured that one out from the get-go. When they tried to deliver me, I just wouldn't fit. My parents were sort of hippies back then, and they were very committed to natural birth, but it simply wouldn't meant to be, and after several presumably very unpleasant hours, they had to go with a Caesarian. All of those hours of straining had taken their toll on malleable infant bones and tissue, though; for the first few weeks, until things took on a more normal shape, my nickname was conehead. My father's comment was, "Well, I guess we can always buy him lots of hats."
That passed, difficulties didn't. For weeks after I learned how to read, I pretended I still didn't know how. I don't remember why. When they finally figured it out, I switched tacks and read every word that was put in front of me, out loud, at the top of my lungs. That messed with 'em.
One day, when I was maybe four or five, I decided I was never going to eat another fruit or vegetable again. Now I think every child decides that at some point, but I was dead serious. If there were any on my plate, I wouldn't eat them, no matter how long I had to sit at the table. I always lasted longer than my parents. My mother got desperate, and started trying things like pureeing carrots into tomato sauce. I could always tell. Once, my parents got a whole basket full of blueberries, and fed them to me, by hand, on the premise that they'd keep doing that until I swallowed one. I spit out the whole basket.
Not long after that, books with titles like How to Raise Your Strong-Willed Child began to appear in the house. That backfired. Sure, my parents read them and took their advice, but I read them too, when my parents weren't looking. Whenever they tried one of the strategies from the books, I would tell them what book they had gotten the idea from, and suggest a better one. Ask my mother about that one, if you ever meet her; I swear she still gets angry about it today.
I learned the truth about Santa Claus from reading an article in Parenting Magazine about when to tell your kids about Santa Claus. Then I didn't tell my parents that I knew.
My parents wouldn't let me watch any TV except an hour of PBS a day. I snuck back into the living room at night and watched the Home Shopping Channel for hours, not because I actually liked it, but because it seemed like the exact opposite of PBS.
If you're deciding to have children, think carefully. You might get one like I was. I don't plan on ever being a father. I know what my genes are capable of.