He'd just gotten out of rehab with the thought in the back of his mind, "I'm going right back to what I was doing before"...and wrote this chorus:
And when I'm gone, just carry on, don't mourn, rejoice
When you hear the sound of my voice
Just know that I'm lookin down on you smiling
And I didn't feel a thing, so baby don't feel no pain
Just smile back
Maybe he wasn't actively thinking it at the time...but I wonder if subconsciously, he wrote those lyrics because he had this feeling he was going to wind up dead sooner rather than later.