"Sleep" has a loose definition and going by the least restrictive one, I cannot go without sleep for more than 18 hours. My brain just stops working. I've been

"Sleep" has a loose definition and going by the least restrictive one, I cannot go without sleep for more than 18 hours. My brain just stops working. I've been "awake" for 42 hours before, but the the second day was probably the least productive one out of my entire life, and I don't even remember it at all, it's like it never happened.