I've had a baby in my mid thirties, she's now 1. It's a massive shock to the system, you basically have a new boss, who is on your back all the time, has no patience and will set deadlines for NOW with no warning and SCREAM at you if you don't hit the deadline. And you still have a work boss when you go back!
Three meals a day with a baby who smears food over their face, hair and into their eyes (it turns out that bibs don't prevent this) plus dropping food and water on the floor/at the walls!!
Poo nappies which at best are smelly, at worst explode up their back even with the most expensive nappies, and mean you have shit on a baby, baby clothes and potentially furniture, flooring, pushchair or car seat.
If I want to have a shower and my husband is at work, I have to bring her in the shower room with me. She cries and shakes in terror if she's in the bath with me as doesn't like the water coming out the shower head to get on her, but if she's let loose in the bathroom it has to be clean and baby proofed. I sellotape the cupboards and toilet seat down!! She also whinges and cries if I do more than a quick wash, which means I rush through it and am less groomed these days. This also translates to drying and styling hair and putting makeup on.
Your nice outfit you've put on gets covered in snot/food/random crap they've found despite your best efforts. See also furniture and walls.
The nursery can call at any moment to say the baby is unwell and needs picking up within the hour. You have no idea how long the illness will last.
It's TOUGH. But then things will get better when they can understand more and talk and learn how to use cutlery (I haven't got to that bit yet!).
The other thing is sleep. You might get lucky, or you might not (like me 🫠) and there is basically nothing you can do about it.
You have the child you have, and they are who they are. Some babies are easier than others but it's just luck what you get!
I've focussed on the baby stuff because that's all I know so far. It's been about three times as hard going as I imagined it would be.