Project Sleep also has some really good resources on their website with their Nerd Alert Series that may help.

If he reads, a really good book is Julie Flygare's memoir, Wide Awake and Dreaming. The other thing is that the weekend forces him to stay awake from Friday morning until Sunday night and requires him to do things that he would normally do on a regular day. Basically, sleep deprive him, and then expect what is usually expected of him, at the speeds, and level of completion/satisfactory as you would normally expect of him.

When you find out, let me know. My husband loves me, but has a "push through" attitude. Trying to explain that pushing through for me doesn't work, because narcolepsy will win. I will eventually fall asleep and it also causes automatic behaviors. Unfortunately, people can't truly understand something they have never been through, however.
We are in marriage counseling and communicating more to understand each other's viewpoint better. Narcolepsy affects me and therefore affects him and it's hard for either one of us to accept.
Educate him through facts from relevant sources, show him examples of other people's stories and struggles, maybe even have your doctor talk to him.
Best of luck! Invisible illnesses are hard on everyone.