I think we sort of rate insomnia internally very differently. Me, I allow to be awake about 2 hours before I start thinking I have a trouble falling asleep. I know I can function the next day losing 2-3 hours so before that I'm sort of not concerned and I don't count that as insomnia.

But we all have different needs and different references. If I only had a hard time falling asleep 1-2 days a week I'd see that as being healed from my sleep disorder. Yet again, different views.

I'm not sure there are any external numbers for when it is insomnia.