I always saw myself having three children. I don't really know why exactly, but I do know that as the younger of two, I always wished there was an extra option to play with when I was growing up. My brother and I didn't always get on, and I yearned for a sister to gossip and share clothes with. My mythical sister would be my best friend, and even though she never existed, I missed her.
So when I was a mother of two, I knew I was going back for a third. I spoke about it with friends and family – some thought I was mad, but others told me third children just "slot right in" with your existing family.
"You'll hardly even notice another one," one school mum friend told me. (Spoiler: she lied.)
My third child – a girl who is now seven – didn't slot right in. She was an angry, colicky baby with a mad attitude problem and a mega-short fuse. Luckily, she grew out of that after the first few years and is now my little ray of sunshine. But there's something else I've noticed about having three kids: it's expensive.
I know, it's not rocket science – three kids equals three times the expense. But I have to admit, I didn't really think of it that way when I was deciding on the size of my family. I just thought three would be lovely.
But there can be so much incidental expense when you go from two to three children. First, we had the car issue. I had two children in car seats, which made the back seat of my car incredibly squishy for a while there. I almost bought a new car, but having three small children meant I was also poor, so a new car was an extravagance I could do without.
Instead, my now 15-year-old – who was eight when his little sister was born – sat in the middle seat at the back, holding everything in and looking quite uncomfortable. He never complained, but I could see it wasn't ideal.
Then there is the idea of going to any kind of family show. If you're lucky, tickets to a show will cost $80 each – so that's $320 to take my children to an hour-long show that – let's face it – I'm not even going to like.
And when you add on going for a meal or grabbing snacks, we've waved goodbye to nearly $500, when my kids probably would have been just as happy with a pizza and a movie on TV at home. (And if any of those kids are caught falling asleep or whingeing at one of these events, I reserve the right to entirely overreact as I think about how much dosh I wasted on this fizzer.) It's so much, I may as well have taken them on a holiday.
And that takes us to holidays. If I want to go away with my children and my partner, that's five of us – and many hotel rooms aren't designed for that many. That means adjoining rooms – so paying for two rooms instead of one. Cha-ching.
I'm yet to take my family on an overseas holiday but that's on the agenda for next year. The idea of how much the flights will cost is already giving me a rash.
My point is that doing anything out of the ordinary seems to cost a bomb when you've got three kids (and if you've got more and make it work, I tip my hat to you). Yes, I know that we can have lots of family fun for not very much – and that's what we do most of the time. But my point is that I didn't realise, when I decided to have my third child, that I was signing up for a lifetime of cheap and cheerful – and that the decision to do something out of the ordinary would be so prohibitively expensive.
I'm attached to each of my children now, of course, and I wouldn't hand any of them back, but I just wish I'd really understood what I was signing up for.