Couldn't sleep last night. My head kept thinking and thinking and it wouldn't close down for rest. I was thinking on and on and if I tried to divert my mind to something more relevant to pre sleep crank-down, it backfired

a)I started by thinking about adoption vs own progeny. I was thinking about nature/nurture, selfishness of my own genes and so and so forth.
b) Suddenly looked at my arm and it looked like a leg of meat. Thinking about cannibalism.
c) Realised I'll be dead sooner or later, point is to be happy. Thinking about how to be happy.
d)Tried to think about lighter topics like blue skies, thought about C02 emissions, tried to think about dolphins, and I wondered which species made it on the endangered list this year, thought about beaches, thought about the report which said no oceans are pristine anymore; decided that nature was not a good topic to muse about. Tried to think about my favourite couples in literature, but then I was thinking about small pox and infant mortality and labour-related deaths.
Pessimistic
Thought about universities, life, death, stars, books, trees, turtles

I didn't worry about any of these, just thought. And every thought budded off to another. My thought chain would have looked like a yeast reproductive cycle.

I slept past three finally. Three being the last time I remember on the air-con remote. It was getting too cold and I turned it down a bit.