This post was co-written with Sarah Thompson.
Everybody knows about the big changes that happen, post-parenthood. The exhaustion and lack of sex - these are well documented. But it's the smaller things that make you really want to take a look at yourself.
1. You pretend to love camping
As children we went to generic Spanish resorts where the food came in a plastic basket and the ice creams were rendered as frozen lemons. Our parents ignored us and we had the time of our lives doing colouring competitions while they got drunk on sangria and had affairs. These days it's all about booking somewhere smug in Dorset with compost toilets. It will be raining, and like being at home, but without the childcare and hot water.
2. The books you read are dull
Back in the day you probably read all kinds of things - bestsellers, magazines, old novels that make you look clever on the Tube. These days it's all tedious books with titles like 'The No-Cry Sleep Solution'. Most play on fear - that you're doing a crap job, that you're letting your baby sleep at the wrong times, that your baby will be morbidly obese and die of diabetes because you forgot to do tummy time. Avoid them.
3. You become an advertiser's wet dream
There was a time when all those cars driving through mountains in the mist washed over you. You were no more interested in Daz Ultra's stain-removal skills than you were your local kerb refuse-collection times. But never before have you needed so much stuff. And never before have you stayed in and watched so much TV. You are also sentimental, and prone to getting teary at John Lewis ads. No wonder the marketeers are rubbing their hands.
4. Buying a massive telly becomes a good idea
Post-kids, the maths on cinema trips no longer works (when you're looking at £30 for a babysitter, before you've even thought about tickets and popcorn, it had better be a bloody good film). Which means that if you're going to see anything made post-Avatar, you'll have to watch it at home. Doing so on a 20" cathode ray really isn't the same, even if it does stop you spending five quid on a giant cup of watered-down Sprite.
5. You become a hypochondriac
It starts with the late-night hospital runs. After memorising the meningitis checklist (boy, that's a great leaflet) and being sleep-deprived into Homeland-style hallucinations, you become a regular at A&E, racing there every time your baby has a temperature and cries because you shine a massive torch in his face (it says they don't like bright lights!) Before long you're diagnosing them - and yourself - with the whole gamut of tropical diseases and Victorian conditions.
6. You go mental over primary schools
Before you had kids, you watched as your friends humble-bragged about their local primary's tiny catchment, or found Jesus two years before the applications deadline. And how you enjoyed judging them for it. Then you had your own kids and realised that the devil might have the best tunes, but God's bagsied the schools. So now you torment yourself about whether you're doing your child a disservice by not finding Jesus.
7. You learn to embrace plastic
There was probably at least one occasion, pre-kids, when you visited the house of a breeder friend and wondered what they were doing with all that Disney Princess tat. If/when I have kids, you won't see my parquet eclipsed by the contents of the Argos catalogue, you thought. They'll have a Melissa & Doug sushi set, one of those ride-on wooden ladybird things - and that's it. Then you see the price of tasteful toys, and realise that kids hate them, and it's Fireman Sam all the way.
8. You're forever wondering what to have for tea
Time was you gave no thought to what you'd eat that night. Why would you? You might eat out, or pick up a takeout, or one of those pasta sauces in the plastic tubs that seem posher because they're refrigerated. But kids bring with them a self-imposed pressure to cook proper meals. And unless you're OK with spaghetti Bolognese every night for the next 12 years, you will find yourself thinking, at least once a day, what the hell are we going to eat tonight?
9. You give in to pink (see also: plastic)
Before you had her, back when you had this parenting lark sussed, you plonked yourself right up there on the moral high ground about pink. For a while you might hold your own with dungarees and Brio, but there will come a point when she only wants to dress as a snow princess and tells everyone she meets that growing her hair is her favourite thing to do. And you will be powerless to fight it. Or too busy doing your make-up.
10. You spend your life at the post office
Because you don't visit actual shops any more, and you're a sucker for a flash sale, you now get to spend hours queuing at the post office, returning clothes you wouldn't have looked twice at on the rail.
Alex Manson-Smith and Sarah Thompson blog at www.youresomummy.com