If you are afflicted with insomnia you are unable to go to sleep on a regular basis, which will often make you tired in the morning.

Insomnia is a condition in which you find it difficult to sleep, but it does not necessarily make it impossible.

I would hate to have insomnia since I like to sleep quite a bit, though it could perhaps keep me from sleeping a little too much I suppose.

Someone with insomnia will find it difficult to go to sleep, but once they do it will not necessarily cause them to sleep any less comfortably than the rest of us.

For someone with insomnia, going to bed early in the morning instead of late at night may be normal, though they could have been lying in bed for hours in the first place.