Something pretty odd that's happened to me on more than a couple of occasions:
I'll wake up in the morning, and then a couple minutes later people start sending me messages on Google Hangouts, so my phone's making a bunch of noise. If it's early enough in the morning, some of those messages will even say things like, "you're up early."
The thing is though, I didn't even touch my phone yet. I didn't even look at my phone.
Messages like this don't tend to wake me up, but instead I don't start getting messages until just after I'm awake.