I assumed that everything would be instinctive so didn't read any books or worry about asking too many questions, other than labour questions!
When baby arrived I had no idea why he was crying. I would feed for hours on end and find that every time I tried to put him down (he appeared to be asleep) he would wake screaming until picked up again. By the 3rd day I had held him non-stop for 12 hours. This even included holding him as I sat on the loo, as I couldn't bear his piercing scream!
This was NOT what I have expected. I thought I'd know the different cries, but all his cries seemed the same - loud and piercingly urgent. I would feed, burp, cuddle and nothing seemed to really work consistently, and I was completely out of my depth.
And then I discovered he had severe silent reflux so would have been in a lot of pain 24/7. Even once the diagnosis was made, I had very little support or direction with how to manage him (other than being given a prescription). I'd say that it took me a good few months to start getting the idea of how to manage him, and it was mostly experiential learning. Definitely not instinctive.
However, I am pregnant again with my second now, and am optimistic that it will be different this second time round. It would be incredibly unlucky to have two severely reflux-affected babies and so from just that one point alone I anticipate it being easier. I also stumbled across Dunstan Baby Language (you can find it on youtube) and could identify the different sounds with different cries. I found a little video clip I'd made of the baby crying while I tried to settle him, to demonstrate how he could only settle with a dummy (which, by the way, was instantly), and was amazed to now be able to recognise in hindsight the distinctive cry for tiredness that he had been making, which at the time I'd missed. I remember at the time knowing he must be tired because he'd had a busy morning followed by a feed, nappy change, and burping, and had not slept for some time, but it wasn't led by some instinct over his cry. Rather a practical working out of what the most likely explanation was, sort of 'process of elimination', if you like.
Some people report instinctively knowing what cries are and what to do, I just was not one of those lucky parents, even though I had expected to be! So I suppose the take-home message is, if you find it's harder than you thought don't beat yourself up about it, you probably just have to learn it experientially like I did. Good luck though, hope you're an instinct-led parent and that you find it natural and easy! :)