My answer: 

The whole “drowsy but awake” thing is really misleading. It really should be “ready for sleep but awake.” The problem is that our image of “drowsy” as adults is really different from how little ones look when they’re “drowsy.” Just because a child’s eyes are open doesn’t mean that they’re as awake as we’d like them to be.  If your child is falling asleep faster than 15 minutes OR if a bottle or rocking, etc. are the last thing that’s happening before going into the crib, chances are, they’re farther along the road to sleep than you think.

 When they fall asleep super-fast, it means they went into bed maybe 80% of the way to sleep and they’re really only going 20% on their own. We really want them going more like 80% of the way on their own so that when they wake at night at 80% awake, they know how to get all the way back to sleep and don't need help getting to “really drowsy.”

 

Also, remember that for livewires, sleepy signals are a sign of weakness. They are not going to show you that they’re tired (honestly, they may not even know it themselves). Make sure that rocking, nursing/bottle, etc. are really separated from going to sleep. If they are…and your child is still falling asleep really fast, make sure they’re getting enough naptime and then back bedtime up a little earlier…so that they’re really making that trek to sleep mostly on their own. 🔆