When you’re having a baby, you expect its arrival to be the Great Unknown: you’re going to jump off the edge of a cliff in the night, with no idea what awaits you. But once you get into it, you’ll get into a rhythm, and the changes from then on will be incremental and manageable.

Not so. Not so at all.

Sure, the birth and first month is like leaping – falling – into the abyss, but gradually you learn how to fly. You learn to interpret the sounds the baby makes and what they mean, become adept at nappy changing, feeding, prepping bottles, soothing her. You work out ways of carrying her that are safe and don’t break your back or your arms, get into a routine, discover you can cope with the lack of sleep and the irritations of cold or skipped dinners, vomit-stained clothing and the ever present weight of responsibility. Things are getting easier. The future looks rosy.

And then, around three months, it all changes again.

She suddenly makes different sounds, different facial expressions. Whereas before, you knew exactly what she wanted and could meet her needs right away, now you can’t anticipate them at all, and you only realise she wants something after she’s started screaming. But on the plus side, she starts to sleep through the night and you have time on your hands and no idea what to do with it. You’re now an expert at nappies and bottles. You’re finally getting a handle on this parenting thing.

And then around five months, it all changes again. She wants to roll over all the time, so nappy changes turn into a nightmarish battle of wills. She starts waking again in the middle of the night for two hours at a time, and you’re so out of practice at missing sleep, it hits you worse than it did the first time around. She wants solid food – well, mush – because the milk just doesn’t cut it anymore. And everything within arms reach is a potential hazard that if she gets her hands on goes straight into her mouth and causes her to choke.

But you invent new methods to cope. I kept losing count of how many spoonfuls of formula I put in her milk as I had to keep one eye on her, so I’ve scrapped the numbers 1-7 and replaced them with the words ‘Thumb, pointer, middle, ring, pinkie, thumb, pointer,’ along with visualising the relevant fingers. Such an effective method, I can have a conversation while doing it and still keep count.

And changing her is so much easier if you give her a plastic baby coat hangar to play with, as it keeps her on her back and keeps her hands busy (and thus out of her own poop). [But a word of warning on this technique – never use something big, like a teddy bear. I made this mistake yesterday. The first thing she did was rub it between her legs and smear poop all up her belly, so I tossed it aside and gave her a sock instead. Finished, I turned to recover the poop-covered teddy bear to find the dog licking it clean. Gross does not describe it!]

We are approaching another change. In the past three weeks, from six-and-a-half months to now (seven months and five days), she has learned to crawl, sit unsupported, remove her nappy, manoeuvre herself anywhere she chooses to go, throw her dummies across the room, and speak, albeit in Spanish (‘habla, habla, habla, habla’, which prompts me to reply ‘Espanol? No habla Espanol. Habla Ingles, por favor.’).

And suddenly she’s decided she wants to be a drummer. Everything’s a drum to her – the tray table of her high chair, her toys, the floor, the sofa, her inflatable donut chair, daddy’s belly, mummy’s boobs. It used to be ‘can I pick it up, can I put it in my mouth?’ It’s now ‘can I pick it up, can I slap it and make a noise, can I put it in my mouth?’ Anything comes on TV with a heavy beat, like the intro to Modern Family, she stops what she’s doing and stares transfixed at the screen. Weirdly, she didn’t bat an eyelid when a compilation of old Sugababes videos was on, but put on Bring Me The Horizon’s ‘Sleepwalking’ or ‘Shadow Moses’ and she’s fascinated (look them up if you want to know why that’s so unexpected! And yes, my musical tastes are eclectic).

And she’s started hooking things over her feet – any hoop or ring toy she gets she tries to turn into an ankle bracelet. The developments are coming so thick and fast – in sitting, crawling, walking, talking, facial expressions, reaching, holding, manipulating, weaning – that it’s hard to keep up. And she’s reached the point where she suddenly gets clingy and shy. A couple of weeks ago, she’d have gone with anyone; now, she glances at strangers then buries her face in my chest before glancing out again, or looks to me as if to say, ‘Is this okay, daddy? Are we safe? Or should I show this person the door?’

According to the Health Visitor, she’s way ahead of the curve, and she can’t believe how these developmental milestones have been reached so close together. Normally, she says, they’re more spread out so you have the chance to process them.

The end result of this is that Lizzie and I both feel we’re walking along the edge of an abyss. We can feel a giant change coming, a truly Great Unknown just ahead, invisible and unavoidable. We don’t know what it is – walking, words, a rudimentary nuclear reactor. We keep expecting to walk into the nursery in the morning to find her sitting dressed on the floor with a cup of tea, asking us whether we’d like one lump or two.

It’s not a very comfortable feeling. It feels like it did the week of the due date – like something huge and life-changing is rapidly approaching and we don’t know how we’ll cope and if we’re sufficiently prepared. Yet again we’ll have to find a way to adapt. And honestly, we’re both a little terrified of this unseen future.

So if you think having a baby will change your life, you’re wrong. It will change your life, then change it again, and again, and again, and again, and again…