Insomnia Then vs. Insomnia Now

As I have learned in the last few months, insomnia can strike at any time for a number of reasons. Here are a few:

Worry
Before my surgery, I had a hard time falling asleep most nights due to worry about what was going on inside me, whether I would wake up from general anesthesia, and how much it would hurt after the operation. (I know, why worry about the third one if I was worried about the second one? And yes, that question kept me awake some nights too!) So I would lay down in bed and then get up and pace and finally be so tired I couldn't keep my eyes open.

Recuperation from major surgery
After the operation, once I started feeling less tired in general, I discovered that no matter how tired I felt I was wide awake once I turned the light off. Maybe sleeping in a seated position on the sofa contributed to that, I don't know, but the solution seemed to be mindlessly jumping from website to website until 2:00 a.m. and then sleeping until 10. I'm assuming that was just my body adjusting itself since my sleep patterns slowly returned to normal.

Completely Random?
And then there's last night. I stayed awake a little while longer than Jon and finally felt tired. So I went to bed and all of a sudden there were tons of "urgent thoughts" racing around my mind. After about 45 minutes I drifted off only to wake up again at 2:40. Uggh! The internet didn't seem to do the trick and around 4:45 I talked to myself sternly and sent myself to bed. Now brace yourself for this shocker: 100% ineffective! Anyway, after another half-hour (or hour?) of tossing and turning I finally fell asleep again, but 8:30 was my final wake-up time. What an annoying night! And why did it happen? I mean, really, what are the chances that a 32-ounce Coke and a 20-ounce Starbucks, both after 3:00, could have had anything to do with my restless night?