That, even first time, it can all happen really quickly. Too quickly even to have any of that mythical pain relief.
That anathestics can make you shaky, for hours.
That maternity wards are really, really hot.
That there are never enough midwives, but they are all lovely.
That maternity wards are chocca in the middle of September!
That there is no peace or quiet anywhere in a maternity ward.
That the shops will still be open after the baby is born.
Despite the last point, it is really useful to have a full freezer and a milkman.
It won't be anything like you expect.
That contractions may get closer, but be shorter, than what you are told to look out for, and come in when it happens.
That the most liberal earth mother can scream for an epidural, and the most orthodox, straight laced woman will happily sit in a warm bath.
That TENS machines are rubbish.
That Primark knickers are WAAAAAAAAAAY cheaper than disposable paper post-birth knickers.
But if you go down the Primark knicker route, you will still be wearing them 8 moths later, because you havn't actually thrown them away.
That your middle doesn't go flat straight away (I knew this, but I also know someone who instructed her DH to bring in her skinny Diesel jeans, and went home in his old track pants, which were the only other item of clothing in the car).
That your baby hasn't read the books.
That no-one has written a book about you and your baby.
That however well you think you have researched your pram/baby monitor/changing bag/highchair etc purchase, you will end up changing something you bought pre-birth, once you start using it.
That you baby doesn't care what colour its room is, or what it wears as long as it is warm enough and not too cold.
That babies are more likely to be too hot that too cold.
That the temperature guidelines on GroBags are designed to freak you out.
That changing a nappy and bathing a baby is actually not very hard, and you will be doing it in your sleep in a few days.
That looking after a newborn is not that difficult compared to a frustrated not-quite mobile 8 month old.
That Parent and Baby groups are for the mums (or dads) rather than the babies.
That not all healthly pregnancies result in healthy births. - Sorry, but bit of a reality check there.