I was 95% home, with all the hills and nastiness behind me, when a SUV in front suddenly stops. Both me and the car behind fail to react in time, and AFAICT the car behind smashes me face-first into the SUV's rear window. My bike was a write-off, and a lovely local lady (evidently quite rich) brought me into her driveway and mothered me with cushions, towels, and refreshments until the ambulance arrived. I think I came off lightly, all things considered. Without my helmet I could well have got concussion.
Aside from this, the day was bloody fantastic.