There are tiers to tiredTier 1: "gosh my energy is low"Tier 2: sluggish, brain at half capacityTier 3: actively trying to keep your eyes openTier 4: wired as hell. You feel a little off-kilter but everything seems fine. Then you realize you only thought you ate lunch. In actuality you poured water on peanuts and threw them out. Tier 5: what's going on, did you drive here or did you realize you aren't fit. Are you mid-conversation right nowTier 6: too tired to remember how to sleel