Q&A: One-year-old not sleeping

Once again, when it rains it pours. A grand cascade of 5 emails, and one real-life friend, in the past week asking what the heck is going on with birthday babies. Let me write you a composite sketch of the emails:

"OMG Help! We made it through that !@#$% 9-month sleep regression, and my baby was only waking up once per night (which, believe me, was a miracle) by 11 months. But my baby just had a birthday and is now waking up 4 times a night again. Help me! What am I doing wrong? Why does my baby hate me? Is this ever going to end?"

In the order in which the questions were asked:

You're not doing anything wrong. Your baby doesn't hate you. Yes, it will end.

Your baby is ramping up for the 55-week developmental spurt. I forget what happens at this spurt, and my Wonder Weeks is packed in a box while I paint my living room, so I can't look it up. But there's a great summary here.

It's going to be over in a couple of weeks, and then your baby will go back to sleeping at least as well as before, but maybe even better.

Sympathy, commiseration, anecdotes (either of your kids or of things you did because this regression threw you for such a loop), or any other musings welcome.

Here's my musing: I thought it was so bizarre to get to one year, and then feel like my child was in such flux. It made 365 days seem completely arbitrary. You think, when your baby's an infant, that a year actually means something. To me it just seems like a big period of flux in all sorts of areas.