Took a massive od about seven years ago. Many different types of pills, and an awful lot of them. Sat in my favourite place smoking some pot, waited to die.
My best friend, who I'd known long enough that he would just let himself in to my house, came round unexpectedly. Found me unconscious and called for help. I woke up about 5 days later. They had to put me in an artificial coma to save my life. And it was a neat thing too.
All I knew from the experience? Once you've swallowed a hundred plus tablets, it gets harder and harder to swallow more. Your body fights it and it's very hard to overcome. Aside from that, I basically just fell asleep. Knew nothing until I woke up in hospital.
Side note, do not recommend. It's a miracle I didn't give myself serious lasting damage