It definitely has, I wanted to include the word "permanent" in my definition, but thought it'd be a bit much. I've experienced blackouts, extremely deep sleep (

It definitely has, I wanted to include the word "permanent" in my definition, but thought it'd be a bit much. I've experienced blackouts, extremely deep sleep (where you go to sleep and feel like you wake up a second later, even though 8 hours have passed) and driving on autopilot, where your consciousness just goes away completely, and you find yourself 10 minutes closer to your destination, as if you've teleported. I'm not saying my conscious perception is constant, but if you plot consciousness as a binary variable on a graph (conscious, not conscious), a lifetime would look something like this, relatively constant. Before birth Birth ..... life ...... death .............................~~--------------------------------------.------------------................ . = not conscious ~ = ..? - = conscious And I'd argue that during dreams you're conscious too, you just forget about it, this claim is supported by contemporary research on sleep and dreaming for as far as my pop-psychology knowledge goes.