My gorgeous DS2 is 17 weeks tomorrow and never a great sleeper. Likes to nose around in the day and BF all night. It’s like he’s a baby or something 

I received a “development” email from Pampers today and it mentioned something about “sleep training”? What the bloody hell is that? Because it seems like leaving a tiny baby upset until they go back to sleep alone. And that can’t be right surely? I’ve not done the newborn thing for 10 years but I’ve breastfed and co slept with both. Not intentionally, they always started off in their own cribs.
Can someone explain this to me please?