I rarely suffer from insomnia. Maybe once or twice a year I'll just not be able to shake something that concerns me, but generally I sleep very soundly and deeply. My natural cycle seems to be asleep at 2-3 AM and up at 8-9 AM. These days it's more like midnight to 6:30. Occasionally I'll sleep for 8 hours or more, but generally it's been 6+ since I was a kid. I can adjust my cycle to meet different work demands, pretty much instantly. But I doubt that today I could make the sort of extreme adjustments I could as a teen, like when I came back from backpacking through Western Europe for several months and instantly adjusted to the 10 hour difference upon landing in LA.