In my earliest postpartum days, there were more than a few moments when I felt like an actual unicorn. Why? Well, because I actually managed to sleep when the baby slept. This was after I stopped worrying something terrible would happen to him if I stopped looking at him for even a second, and before I needed to write during his naps in order to pay for expensive habits like eating multiple times a day. Because however well-intended folks are when they suggest to "sleep when the baby sleeps," that advice is basically impossible to follow, and is pretty much a giant lie to parents who inhabit the real world.
Babies can afford to sleep at random, weird times throughout the day and night because they don't have jobs, or other kids to raise, or other responsibilities that require them to not be conking out every couple of hours. Of course, the same typically can't be said for the parents subsidizing their random car-dozing and ring sling-napping. So aside from a few glorious weekend co-naps here or there, for most folks, "sleeping when the baby sleeps" tends to fall by the wayside, kinda like folding laundry as soon as it comes out of the dryer (or folding laundry ever, really).
Perhaps, someday and when unsolicited advice givers finally perfect the technology needed to, "sleep now while still you can!" during pregnancy, it will also become possible to regularly sleep when the baby sleeps. Until that joyous day, however, sleeping while the baby sleeps will remain the lyingest lie to ever lie. It's just not possible, especially at times like these:
When You're Too Nervous To Take Your Eyes Off The Baby...
When my son was first born, he seemed too tiny and precious to possibly survive out here in the non-uterus world. So, naturally, I spent most of my first week staring at him every time he slept to ensure he continued breathing. There's not much sleeping when the baby sleeps when you're anxiously, constantly trying to confirm the baby is still alive.
...Or Too Nervous To Sleep With The Baby
As a converted-by-desperation co-sleeper, I can appreciate that there are lots of people in the world who are too nervous to sleep next to a baby (which is how many babies prefer to sleep). So if you're someone who can't get comfortable sleeping next to an infant, no matter how exhausted you get, you'll probably end up staying awake scanning social media your phone while baby snoozes on you.
When The Baby Won’t Sleep
If you have a baby who won't sleep at all unless they're on or next to you, and you can't or won't sleep like that, then so much for that.
When All The Construction In The Universe Is Happening Outside Your House
Sometimes, other people — who aren't nearly as concerned about your sleep schedule as they should be — decide they want to build roads and houses and stuff right next to your house.
Unfortunately, construction workers do not keep random baby hours, much less your particular baby's random hours. They typically like to build things in the daytime, when there's enough light to actually see, and then go home to their families. That means their "building things time" will necessarily overlap with some of the baby's sleep times.
Some babies manage to sleep through all that noise. Many grown adults, myself included, cannot.
When You Have Bills And Can't Get Paid To Sleep
"I know you need me to pay my mortgage, Scary Bank Person, but everyone I ever talked to during pregnancy told me to sleep when the baby sleeps, and I've yet to find an employer who will approve four paid naps a day."
When It Takes An Entire Newborn Sleep Cycle Just To Fall Asleep
Too frequently, it takes me as long as an hour and a half to actually shut off my brain long enough to fall asleep. Unfortunately, that is often quite close to the exact length of a newborn daytime nap. There are few things crueler than hearing a baby cry juuuust as you're finally drifting off.
When Your Older Children Need Raising
Sleeping while the baby sleeps is all well and good, unless you send your kid to one of those schools that wants you to like, pick them up every day, or have one or more of those kids who need supervision and actually want to eat on a regular basis. (The absolute nerve of them, right?) If you don't have a partner or someone else around to handle that stuff, so much for sleep.
When People Keep Ringing Your Doorbell
There's a special place in hell for people who ring a postpartum mom's doorbell, even when she puts a note on the door telling them not to. Some ding-dong-ditching teenagers and FedEx delivery guys just wanna watch the world burn.
When Your Older Child Yanks Down The Curtains In Your Bedroom
If you are fortunate enough to have great natural light in your bedroom, but unfortunate enough to have a big kid yank down your curtains (rod and all) before you can replace them, it's tough to get sleep in the daytime. Especially if you don't own one of those sleep masks ‘cause once upon a time you were a normal person who didn't follow a cat's/baby's sleep pattern, and slept mostly at nighttime when the sun doesn't burn holes in your eyelids.
When Your House Refuses To Clean Itself
Sure, rest is a higher priority than living in Martha Stewart's fantasy home. But at some point, when mold is using your dishes more than you are, something has to give. Hint: it's usually a daytime nap.
When You Have Business To Attend To With People Who Keep Regular People Hours
Sometimes you need to buy food, or ship packages, or to do other things that typically happen during prime napping hours. If only the grocery store folks could get with the "sleep when the baby sleeps" program, right?
When You Want To Interact With People Who Aren't Your Baby
As the construction workers, grocery store employees, and others have made abundantly clear, most people in the world don't keep baby hours. So if you want to have any kind of social interaction with people who talk in words instead of screams, you have to pick times when they're awake. That's usually daytime, my friends, which means it will probably coincide with times when the baby sleeps.
When The Baby Only Wants To Sleep In A Moving Car
I mean, you could sleep when the baby sleeps in the car, but unless you have a professional chauffeur I'd strongly advise against it.