Have you ever went under anesthesia? Well there is a drug they give you that relaxes you and then puts you out like a light. Before my surgery as they were administering this drug I was full of a list of questions for my doctor. Supposedly I got through all of my eleven questions and got my eleven answers.. however I had no recollection of such when I woke up after surgery. So I asked them again, and everyone laughed! My doctor told me and my husband and mother-in-law.. "Watch she isn't going to remember a thing." He was right. If your sleep drug works along the same lines as the relaxent used presurgery.. then it is probably the drug. It must start shutting down your brain from storage functionality up.. until you pass out.

You can check with your pharmacist. They should know the particulars of that drug and any known side effects. Also there should be published public data from the human studies of the drugs approval trials.

Sincerely,
MG