My son is 13 months old and has never been a great sleeper, but for the last few months he's slept well at night (usually with one wake-up/nursing session) and taken at least one decent nap per day, with minimal fussing. Even if we put him down and he doesn't go to sleep right away, he seems content to talk to himself for a bit and then drift off.

This all changed a few days ago. He slept through the night, which is very unusual for him, on Thursday night, and then took a two-hour morning nap on Friday. He didn't nap on Friday afternoon, but we chalked it up to the long morning nap and great night of sleep. He also slept through the night on Friday night.

On Saturday, he took a decent but shortish morning nap. We tried to put him down for his afternoon nap, and as soon as I left the room he started crying hard, which he almost never does at all anymore. It was heartbreaking! He calmed down after 15-20 minutes (just at the point I was going to go in and rescue him) but never actually went to sleep. Bedtime was similar - inconsolable-sounding crying for about 15 minutes, but then, fortunately, he fell asleep. He woke up around 5 to nurse and wanted to nurse for a looooong time. I put him back in the crib and he went back to sleep until 8:15, which is about two hours later than his usual preferred wake-up time.

Since he woke up so late, I decided to try skipping the morning nap on Sunday and putting him down early for his afternoon nap. More hard crying and another failed nap. I then took him to the grocery store, followed by an hour-long walk in the stroller. Still awake. He was actually in a great mood all afternoon - I don't know how he did it. At bedtime, he started in with the loud crying, but only for a couple of minutes, and then slept until about 5 again. Just like the previous day, he nursed for a long time and then went back to sleep until after 8 this morning.

Sorry for the novel - I'm hoping the details will make it more likely for someone to recognize a pattern and tell me what the heck is going on! If you have experienced anything like this, I would love to hear about it.