Some things that I think make it hit differently:
* The house and most scenes are dimly lit
* You see the family in various stages of sleep
* The musical score has some intense crescendo
* The vulnerability it shows
It's a small glimpse of night time in a house with a child that is still transitioning to sleeping on their own. Having had kids, that weight being lifted as they finally "get it" is a unique feeling of bittersweet relief. It also shows the lengths the parents go through to make it a graceful and comforting transition.
Every milestone your kid reaches marks the end of their previous self and we grieve never getting to see that little person again.
Children open your heart to so much joy and so much grief.
This is how I felt about the episode before I had kids. I thought it was a fine episode but nothing special. Onesies was my favorite. Of course, we wanted kids, so that hit me where I was at the time. Now I have a two-year-old, and I "get" Sleepytime. There is nothing extra to explain except that it will just mean more to you.
Not saying you don't have kids, just my own experience with it.
Are you referring to how it references the fact that parents will eventually leave their kids when they die?
That’s only mentioned indirectly by the mom, no?
Is there a deeper story that I am missing?