I didn't really face my first true test of fatherhood until little bub was almost five-months-old.
Mum had been given a few hours off and I was in the pilot seat with a simple mission: keep him fed, keep him alive and keep him happy (in that order).
All was going well until his heel thundered down into a poo-filled nappy that could shake the nostrils of a veteran abbattoir worker.
Don't get me wrong, I'd been happily changing his nappies from day dot - but they were royal picnic affairs in comparison: all gentle Velcro tabs and delicate wet wipes.
This was no ordinary nappy.
No, this was a heaving trench of steaming milk and lentils that could warrant an investigation from a WHO pandemic crisis team.
And not only had he heaved his feet through the quagmire, he had toddled across the bright white bed sheets leaving footprints like some kind of fertiliser-themed Easter bunny.
I'd made a classic apprentice-dad mistake: I'd forgotten to put a drop sheet down.
I had two problems on my hands. Obviously there was the case of the poo-ey baby crawling at top speed. Then there was the laundry: I would now have to wash the bedspread, dry it, and somehow replace it (I used a tape measure to work out the dimensions of the mattress).
Of most concern, I was convinced there were flecks of newborn star dust in my mouth.
Being a new dad, I've discovered, is about being the ultimate support man. There are some things, by way of genetics, culture and personality, that I was simply not cut out for.
During the actual birth I was terrified – but I wasn't really doing any of the work. I was the ball boy as she was facing match point.
In the early days, it wasn't me getting up in the early hours to breastfeed the baby.
It wasn't me trawling online forums to find out what his sleep schedule should be.
It wasn't me picking what clothes he should wear, or what his development milestones should be.
It was his mother, my partner, and the person who I credit with the ability to keep bub and I alive.
Volcanic ass eruptions aside, my first year of fatherhood has been bliss.
Don't get me wrong, as the parent designated to go back to work first it's been a whirlwind of sleep-deprivation, guilt, heart-swelling facetime calls and hurried goodbyes.
But the good times are so good.
I love the way the light falls on his hair, his toothy cheeky grin, his chunky little legs.
At times I'm convinced he is an exact replica of my wife, immaculately conceived without any of my input (a fact she likes to point out).
At other times I see my father – the way he curls his tongue when he's thinking, the gentle inspection of a toy.
This little boy is a vibration of the family trees of my wife and I, which is a profound thought to have when you're trying to pick out the right "flow" bottle teats at Chemist Warehouse at 11pm.
The world is no longer about me, and that's a freeing thought: working for the needs of a child as opposed to yourself gives a greater sense of purpose, and makes 4am alarms all the more bearable.
It's surprised me how much capacity I now have to give love, and to receive it. He's made all of our hearts so much bigger.
I've never appreciated my parents more after becoming a dad to little Lachie, and I've never appreciated motherhood more. It's the hardest job in the world.
If there's advice I can offer new dads, it's this: put a drop sheet down.