I realize that not everyone fortunate enough to have a job works a M-F, 9-5 schedule.
So I am not suggesting that this a universal experience.
But I suspect that I am not the only one who notices something as the week wears on. Let's call it a diminishment of expectations.
On Sunday night, you're thinking "This coming week, I'm really going to get after it."
You plan to move briskly forward on multiple fronts and get lots and lots done. Special projects? Bring 'em on. Extra assignment you need to get going on? No time like the pressent.
Then the week arrives. And something happens.
You find that accomplishing just your minimum required tasks is about all you can manage. And by Friday afternoon your goal might be summarized as "Try to limp the rest of the way to the weekend."
Of course, come Sunday night you are planning to hit the ground running once again.