"so many devices, sensors, things that you're wearing, things that you're interacting with"
I carry a very small number of things that can connect to the internet - my phone, maybe a tablet or a Kindle, and depending what I'm doing I may have a laptop with me. And all of these things currently connect at my whim, and for my requirements.
If I can't control that, I don't want - I'll stick with older devices on which I can. And I certainly have no intention of wearing anything that would connect.
So in this crazy intrusive future you're talking about, Schmidt, there will (mostly) be a blind spot. Perhaps these other sensors will know there's someone there, but they might not know who - unless our increasingly intrusive governments finally get enough biometric data on us all that sensors can identify us regardless of anything we may or may not be carrying or wearing.
Either way, the systems connected to these sensors certainly won't know what I'm going to do when I enter the room, because that information will be IN MY HEAD, which is 100% off limits.