My child was replaced with an alien last night

Seriously, I have no idea what was going on with my kid.
Rowan has pretty much always been an amazing sleeper. He's in bed by 7:30pm and usually wakes up around 6:30am. Once in a while he'll lose his paci and I'll here makes a couple of distressed sounds, so I'll go in, put it back in his mouth, and he rolls over and goes right back to sleep. This happens maybe 1 time every few days.
But last night....
Slept as quietly as usual from 7:30pm to about 10:45pm....then woke up and started to cry, hard. I checked on him, nothing in the diaper, no temperature, calmed down as soon as I picked him up. I held him for a few minutes, he looked drowsy, I put him back down...and it started again. This went on most of the night. I tried letting him cry it out, I tried holding him, I even gave him a bottle and he hasn't had a night feeding since he was about 6 months old. Nothing helped. He wasn't inconsolable - if I held him he would lay quietly and just look at me, eyes wide open. Finally, around 2:30am, I gave him some tylenol in case he was teething and put him in bed with me (in the day bed in his room). He fell asleep (and so did I). I woke up around 3:20 and he was out cold. I put him in his bed.....and about 10 minutes later he woke up and we started again. So I gave up, I have to get up for work at 5:45 and by this time I'd had maybe 30 minutes of sleep. I went to bed with him again and we slept until about 5:40, when he woke up like he was ready for the day to begin, and seemed totally fine.
WHAT THE HECK??? 
Any suggestions? I'm terrified that we're going to do this again tonight!!

 Oh No!! Bella did the EXACT same thing two nights ago! Bella wouldn't calm down for nothing. Did he have any new foods? Teething? That's what i was thinking with Bella!
Jessica

Teething is the only thing I could think of..he hasn't eaten anything new, he has learned any new tricks, but the tylenol didn't seem to help the problem at all. I'm thinking of trying ibuprofen before bed tonight.

Has he learned something new in the past few days? Matty just started walking, and for the two days before he really mastered it and the two or three days after he really started doing it he was EXACTLY like you described. I noticed we had this same kind of pattern when he learned to stand on his own and when he learned to crawl too!

 Bella did learn how to crawl the other day. Now she goes in her bed and crawls when she wakes up and screams!! Never thought of that. 
Jess

He's been walking with us holding one hand for weeks already. When we try to get him to stand alone he just sits down and smiles. He has started trying to, I THINK, figure out how to stand without having something to pull up on. All day yesterday he was assuming what I call his "downward child" position...on hands and feet with butt stuck up in the air. Other than that, nothing new.

Bad dreams, teething, gas pains?

Alex has been doing this more and more lately too!  Though, he doesn't do it in the middle of the night.  I can usually settle him by then.  He typically starts around 11:30pm.. and is inconsolable.  Wants to be held and if I even so much as shift a certain way to make him think I'm going to put him back into his bed he starts right back up.  I have started to think it's his teeth and give him Advil, since as soon as I give it, within 10 minutes I am able to put him back to sleep with just a bit of a bottle down him as well.  

Well, the consensus from the daycare ladies (who have a lot more experience than me) is that his 2 top teeth are coming in. When his 2 bottom teeth came in it was nothing, they just appeared, but apparently the top two hurt a lot more. He had ibuprofen last night and slept a LOT better.

 Yeah the top teeth were a doozy for Alex.  All 4 cut in a 2 week period.  We had teething poo's up the wazoo.. woo did those stink!  I'm glad the ibuprofen helped!