I'm a mom and a long time career nanny. In my career, I once had a kid who sleeps the way you are describing yours sleeps, in a twelve-hour straight run. It is a gift with no negative consequences. Grab that glory and don't look back.

My own kid has always had a late bedtime. I'm talking 9 pm. Even when the book said it should be earlier, nope, not my kid.

I learned from following Dr. Pam Douglas that my kid has a huge stimulation appetite and just hadn't built enough sleep pressure due to not actually doing anything or learning much and when I exposed him to a lot, he went to bed for his night sleep earlier and still to this day that's his pattern. He's 11 months and Saturday we went to a La Leche League meeting, a baby shower, a sprayground, and then a friend's house. He went to bed at 5 pm and slept the night through. Sunday, we went to the farmer's market but otherwise puttered around the house and he struggled to fall asleep by 10 pm. But Saturday's level of go-go-go is completely unsustainable for us, so I've come to terms with a later bed time.

Dr. Douglas's research shows that contrary to not-evidence-based opinion, children fuss not from overstimulation but from understimulation and that children in their first year are primed to be the biggest learning sponges they could ever possibly be so seek all the data and most parents do the opposite of meeting that need. 🤷‍♀️ I mean, she's got sources and peer reviewed papers and all. But for me, all I can say is that my kid responds better now and also when he was a newborn to more exposure to the things rather than less exposure to the things. And really, the whole goal is to find what works for the kid you have, right?