Night terrors are actually quite normal in very small children. All the studies I've read show they grow out of them. Sleep is one of those things that can be a mix of nature and nurture. My DH can go to sleep roughly 30 seconds after closing his eyes and not wake till morning. I sort of want to kill him for that occasionally.
I don't think insomnia like you describe is normal and feel they should've done a sleep study on you and find out if there is some disorder at play. I deal with some extremely irritating insomnia and have most of my life, part of it has to do with a rough childhood and racing thoughts as soon as it turns dark. I find if I stick to a very strict schedule (waking at the same time even on the weekends) it helps immensely with my insomnia. I also use a sort of meditation before going to sleep and won't allow my thoughts to dwell on worries. Instead I will try to remember memorized poems, movie dialogs, stuff that has nothing to do with reality. If I am having trouble sleeping I get out of bed so I don't associate insomnia with my bed. I have to program my brain to think bed=sleep. That's all the advice I can offer, insomnia sucks.