So, for reasons unknown, I've had really bad insomnia for the last few days. Basically, I haven't slept.

I've done some looking around and found some people saying how your brain goes straight to REM sleep if you're tired, but some say it's harder to attain lucidity. Could someone please clear this up for me? My life is a living Hell because I keep failing at every attempt to become lucid... Is this the reason?