It's calling my boss on my very first day of work to apologise and say that I won't be coming in as my child is ill and vomiting and I will therefore be having to stay at home to take care of them. (I almost cried every time someone asked me this morning, "Aren't you supposed to be at work today?" and I nodded my head with, "Yes, yes I am - but I won't be.")
It's having... let's call them discussions with my husband over whose work is more important and whose role it is to stay in.
It's walking out of a library with four random books I've snapped off a "Featured" shelf because I don't want to spend time looking for what I actually want to read amidst my child hollering and fellow library visitors looking on with that pitying, understanding expression.
It's staying up almost the entire night with a child who's ill, then catching up on sleep the next two days, and when another rough morning starts before it's even 5 am, feeling that swollen, grating sensation of heavy eyelids and knowing why I never want to go back to those early parenthood nights of getting up three, four, sometimes five times a night, and needing to function to an acceptable standard in-between those nights also.
But most of all it's thinking, as much as many things have become much more colorful since kids have come along, by golly do have some things become way, way more difficult to accomplish again.
Even a feat as simple as showing up for work on my first day.