Typically I'm pretty handy when it comes to things I know like most I presume. When I'm punching the envelope I slow down and still manage to throw myself into a nine line bind.

I bought what is called a Bark Box for one of my saws; a friend mentioned it really improves saw performance. Installing the box is simply a matter of replacing the muffler cover with said product.
I begin by removing the muffler box, making a necessary mod to the spark arrestor, and replacing the muffler box. Mount the muffler box, check. I can't line up the through bolts to the engine case because something is not quite seated squarely. In the process I break the freaking gasket into pieces, which I declined at the saw shop btw. Back to town for a gasket.
Neighbor shows up for a beer and is watching me drive the struggle bus. He asks if I want a hint and he says to just start the through bolts then mount the box. Why didn't I see that? That was easy.

Then today I'm cleaning the house chimney, stove and cap. We burn 3-4 cord a year. Creosote is inevitable as the stove pretty much runs 24/7 all winter. It's a genuine PITA to get a really good cleaning on the chimney cap. The contour is fully angled like a conquistador hat. I spend a great deal of time scraping and brushing. My wife wanders by and says "Why don't you try oven cleaner?"

Well, holy shit people, I am here to tell you oven cleaner worked INCREDIBLY well on the the cap.

Why don't I think of this shit??

Because "that's the way we've always done it."

I think the single most powerful question to ask when solving a problem is

"What assumptions am I making?"

Then, ask the followup

"Are these assumptions valid?"

a priori (before the act) assumptions always create boundaries for acts.

If it weren’t for the hard way or the last minute, I swear I would get nothing done.