Kids sure are unpredictable.
our 1 year old sleeps like a champ, 8pm to 7am every day. Has been that way for months. All of a sudden last night he wakes up at 3am screaming and crying. Wife gets up to hold/rock him back to sleep, no go. 30 minutes later and he's still screaming and crying. Then we swap and I try the same, rock him, walk around the house with him, etc. Nada. At this point its well past 4am and he's still inconsolable. I finally just turn on the living room light, set him down, and he just goes over to his toy box and starts playing like its the middle of the day. He was up for the day at that point, my wife fed him breakfast at 5am.
So yeah, I got about 3 hours of sleep last night, that was awesome. I don't know what the hell was up with that, but I hope it doesn't become a regular occurrence.