Like you'll wake up at 12pm and realise you haven't showered in days and haven't changed your clothes? Or you'll realise you haven't left the house in weeks? Or you sit down to play your favourite video game and feel no enjoyment? 

Then it hits you that it's so normalised that you hadn't even noticed. 

It hits you that you can't remember what you've been doing for the last couple of weeks, what did you eat? What did you say? Who did you talk to?

It's just a blank expanse stretching behind and in front of you, and you forgot that it isn't normal.