Well, if you bf, they need feeding every few hours, bottle fed possibly a little more.
They need changing a lot as the poo has a habit of leaking, usually just as you want to leave the house.
Leaving the house can take a while, for above reasons, just as you change baby wants more milk.
Often babies like to sleep in the day and wake at night. Now some people are able to go to sleep in the day as if it is night-time, i personally cannot easily do that.
Just as you establish a sleep/eat/change routine, it changes and you have to change your own sleep/eat/change routine to fit.
You will find it hard to drink a hot drink again.
You might, might be lucky and have a baby who is chilled and sleeps well quickly, eats well quickly, does not do runny poos, is happy and content all the time, suffers from no colic etc.
And then, any time from 3 months onwards they can show signs of teething, even though they might not get a tooth til 6 months plus, then, you have nappy rash, sleepless nights with a crying/screaming baby and don't know why as they are too young to teeth, but clearly something is wrong.
It is not really that bad! It is great, but it is constant for most people, changing, feeding, washing, sleeping, housework, visiting people, people visiting, changing your social life, drinking less alcohol, and it is hard.
But, the most rewarding experience in the world. I personally found the first few weeks/couple of months blissful and chilled, and the difficulty sort of crept up in intensity as DD needed more attention from me.
But, hopefully you will be like a friend of mine who has had the easiest, most chilled baby in the world and is only just finding it difficult now baby is over a year old and walking!