When someone is continuously doing REALLY stupid things under the influence of marijuana that cause that person embarrassment.
**Lyle tries to roll down the window of a car with automatic windows when the car is off**
Friend in passenger seat: "Ah man, you're failing Lyle.. you're failing hardcore.."
This term describes the nightly experience of those unfortunate schmucks who just absolutely cannot fucking fall asleep, no matter how much thrashing around in bed they do or how much ruminating over past mistakes they indulge in. Instead of falling asleep, an insomniac is simply failing asleep.
Alice: "Wow, you look like hell"
Bob: "<mumble> last night I was failing asleep and couldn't stop thinking about some shit from middle school when I got my bike stolen"