I fall in/out of good/bad sleep periods every several months or so. I'm in a total sweet spot right now (probably a function of my life being so busy since taking on the CEO role at Gnip), and have been for awhile. It feels great! I'm out cold when I hit the mattress, and I'm generally out like a light until the sun starts to peek over the horizon each day. I was poking around my fitbit's sleep data and this chart popped up. Data around my sleep patterns; love it!