Lebber,

There is a difference between feeling tired and being sleepy. A person with insomnia often feels tired but does not feel sleepy. If they do not fall asleep in 10 minutes or so, they should get up and find something to occupy their mind in a non-stimulating way until sleepiness sets in. Boring TV, reruns, etc can help. They may want to take a small sip of water but not enough to trigger bladder sensations. There are known issues for dealing with insomnia and PCS.