With chronic insomnia there is always a lot to the story... which is why over-the-counter and single agent medications don't always do the trick. We need to view insomnia as a symptom and look at what else is going on.
For most of my 20s and 30s, if I couldn't sleep, I could usually point to some anxiety as the cause -- a stimulating writing project, an important exam, a conflict with someone I loved. It's only now, in my early 40s, that I frequently experience sleeplessness for no apparent or obvious reason.
It's all too common for people to shrug off their episodes of insomnia, to do their best to function and cope. This kind of "power through" strategy is rampant in our busy world, but there's no real escape from the consequences that insomnia can bring.