End of the day
You start the day with high hopes ... and then your computer crashes, a family emergency pops up, you're coming up on a deadline and there are two days worth of dishes fermenting in the sink. And it pretty much sucks.
So you take your son out to escape for a few minutes, and you find yourself wondering how you ever got so lucky to be standing right here, right now, with your (your!) kid.
And it's pretty much awesome.