We all know every baby is different, every kid is different and not one approach works for every kid, even in the same family. I am here to provide proof, as it took me having my fourth kid who through me for a loop to figure all this out, once and for all.
She was impatient from the get go. Refused to settle down and nurse right away, would turn it into a screaming match until you have her a few sips of a fast-flowing bottle, and only then would decide to latch on and nurse. This went on for the first month of her life. Refused to be put down to sleep in any position besides her tummy...so she was a tummy sleeper from the start. Bad mom, I know. As soon as she could pull herself up the first thing she learned to do at 9 months-ish was climb onto a tiered corner table and throw pictures off and break them. I knew I was in trouble then. Around this time she started fighting sleep in a major way. No rocking, swinging, cuddling, or reading could settle her down. She would thrash around and scream. So she cried it out for about 40 minutes every night before she finally gave up and would go to sleep. At just over a year she figured out how to push a chair against anything high up she wanted to reach, including the front door chain. By 18 months, she refused to nap. Period. I could spend the entire day trying to get her to sleep and she wouldn't ever. She also hated if you changed her room around or added anything extra into it. I will never forget the terrified screams when I thought she might like some quiet music to sleep to. The evil CD player on her dresser just had to go. She was a terror from ages 2-4. Her sleep was atrocious...she went through a 2 year plus period thinking 4-5am was time to wake up no matter what. I would spend half the early morning hours trying to convince her she needed to be asleep. I thought I was losing my mind, until my sweet understanding pediatrician assured me it was only a phase she would eventually grow out of and told me of his own parenting sleep issues and how he made them tolerable. About a year later she did eventually get better and sleep all night long. But she is still at 15 on a totally different schedule them the rest of the house. She was also the kid, and still sort of is, that you can't show anything to. She refused to learn to write her name with me so she learned at school. She will only want you to show her after she has butchered whatever it was she was working on.
My second child...she took to nursing like a champ and stayed that way for about 10 months. Her infant sleep quirk was that she would get so over-stimulated that she would scream until you put her down...then scream hard for 30 seconds before falling to sleep. She has been the most easygoing of all my kids, even now. As a toddler she wasn't too terrible, could easily be talked out of a tantrum, and loved her naps. As a baby you could put her down and she would sleep on her own. Once in a regular bed, if you laid with her for 1.5 minutes and cuddled she would be sound asleep. She never had any issues waking at night or up at the crack of dawn. She is also pretty easy to figure out. When she was 3 or 4 we started noticing she was stealing cans of soda and drinking them and was getting into trouble but wouldn't stop the behavior. Finally I asked her why and she honestly told me could I just move the sodas where she couldn't find them because she tried but couldn't resist them, that she didn't know how to not drink them. It was the funniest thing, but at least we understood and could help her!
My third child, my first boy. From birth, literally in the hospital this started, he would only nurse every 5 hours and sleep the rest of the time. I never thought it would last but it did. If I tried to nurse him sonnet than 5 hours, like if we were going out somewhere, he would eat them throw up everything all over the place. When I pumped at 6 weeks for the first time I got 8 ounces from each side, he was eating that much. By 6 months he gave up nursing completely in favor of real food, anything and everything that we ate just squished up. He also continued sleeping like a champ. He had no desire to try and stay up late, and needs his 12 hours of sleep, even now. He isn't a party animal who can hang and stay up. If we are watching a family movie and it's 8:30, he will ask to go to bed. He was an easy toddler to handle for the most part, and is still a pretty easy kid despite being hardheaded at times and doing dumb thing, like stealing my stash of candy and thinking I won't notice.
All of these guys started sleeping through the night by 8-9 weeks old. I did nothing at all to help with this. I would just feed them and put the to bed at a normal, reasonable hour.
Baby Number Four has taken everything I knew as a parent about baby sleep habits and thrown it all out the window. From the start, he has wanted to sleep no where else except in my arms. He has never gone to sleep easily for any stretch of time. If you got 2 good/easy days of naps and nighttime sleep with little hassle, the third night would change that. There has never been a consistent way he has ever gone to sleep and stayed that way. Nursing to sleep was the most consistent, but he would likely wake up within the hour and not be able to settle down. Drowsy but awake? Forget it. That might have worked 2 nights out of 200. My pediatrician would ask at every appointment "sleeping through the night?" "NO." And I would get the same lecture about how he could do it and I knew how to get him to do it. Yeah, no I didn't. I did nothing different with him than I did with my other children. But he would never make the leap. He finally slept though the night at 14 months. Right after I totally weaned him. And only in a room by himself. (He slept in our room still at that point because we had not yet moved and were not going to put a baby who was up all through the night in with other kids who had to go to school). Could this have been the problem, that he was still in our room? I doubt it. because we wouldn't even go upstairs to bed until he woke up the first time, even if it meant sleeping on the couches until them, ever hopefull each night would be THE night he slept. Also, my third child slept in our room until he was 8 months old and I was sure he wouldn't be waking up other kids. I never had to worry there, though. We moved, and he started sleeping well in his new space. We could start putting him down drowsy and he would fall asleep in his own. Until he decided he had enough of that and needed someone to stay until he was almost asleep. And then until he was completely out cold asleep. And now lately he has decided he wants to protest even that. So lots of nighttime sleep fighting. It doesn't matter if he is just tired enough or overtired. I have tried adjusting so many things I just give up. Last night in a tired exhausted state, I decided since he wanted to fight so much that he could cry it out. I did the whole comfort after X amount of time, go back reassure, space time out, go back reassure...for 2 hours. And he wasn't giving up. He would settle just enough to seem almost asleep, and then the utter screaming and wailing would come envy and be louder and last longer than the time before. I finally called it and resigned myself to the fact that bedtime is going to be a nightmare with him...until he changes things up yet again. How this is going to work with a new baby, God only knows. Other than the sleep thing, he is an awesomely sweet little baby who loves to cuddle and give kisses more than any of my other kids. He also is so smart but refuses to truly talk, but he has so many people doing things for him he doesn't have to. I bet when Bonus Baby comes around he finds his voice.
So yes, despite being the same people we have always been, and parenting all of our kids in pretty similar ways...it is obvious that not all things work for all kids. I truly wasn't so aware of this until my fourth baby came along and I was first hand seeing just how different one baby could be in ways I had not seen previously.