Serious side effects of AMBIEN include:

• getting out of bed while not being fully awake and do an activity that you do not know you are doing. e.g., preparing and eating food, making phone calls, or having sex have been reported in patients who are not fully awake after taking a sedative-hypnotic. As with “sleep-driving”, patients usually do not remember these events.
• abnormal thoughts and behavior. Symptoms include more outgoing or aggressive behavior than normal, confusion, agitation, hallucinations, worsening of depression, and suicidal thoughts or actions. Visual and auditory hallucinations have been reported as well as behavioral changes such as bizarre behavior, agitation and depersonalization
• memory loss
• anxiety
  
• severe allergic reactions. Symptoms include swelling of the tongue or throat, trouble breathing, nausea and vomiting.

Holy crap. Insomnia might not be looking so bad for some folks. I have been lucky enough to never suffer from the inability to sleep. In my youth, I used non-sleeping as a way to get more done. Apparently, it is not the case for all folks.