There is a time lag from the time your heart stops functioning and the brain ceases to work. This may be upwards of ten minutes. During that time it is conceivable that one knows they are dead. I know, kind of a disturbing thought. The point here is that the first part of the meme, though essentially accurate, is probably not completely true.
The second part is fine as is.
My favorite statement is aimed more toward ignorance, "They don't know what they don't know." One example that springs to mind, I'm male and therefore have never experienced childbirth. I have no idea what the actual process is like from the viewpoint of a baby trying to get out of my body. Same with arrogant people, they don't what to "see" and learn about anything outside of what they already know. SO, they cannot speak on any thoughts or emotions other than what they have, up to this time, experienced.
Hmmm. I don't quite understand the stupid remark. Death is like falling askeep. Not waking up. You may have a dream or two. When i slept, i didnt know what was going on around me. The bottom line is the memories before you die. You can say I've lived a good life and peacefully move on. Who knows whats on the other side of death? There are a billion stars in the sky. I see them therefore i know they're there. Thats all i know. So who really knows whats our next step is.