This story requires a little supplemental education:
thunderf***
[thun-der-fawk]
verb
1. to quickly piece down a tree in large sections, with regard to structures and obstacles, but not grounds.
noun
1. a pretty good name for your next crust metal band.
So, one time, I was rigging out a big Ash in tight quarters. I had an opening for some air mail with a few large laterals and a top over it, and room to fit it big, so big I went. The lowest and largest lateral was 16" where I made my 3-point undercut, a little over halfway through the stem. As usual when I am thunderf***ing (and, as one normally thunderf***s), I yelled out "Thunderf*** HOOOOO!!!," in my best Lion-O (a la Thundercats) just before executing my top cut.
This was before I was religious about bar maintenance.
A quarter-inch into my cut, a burr on my saw bar caught the side of the kerf. My arrogant smile took a crap as the broomstick ends of the branch swung down almost plumb, before the fibers let loose, as I desperately and hopelessly ran my saw, stuck against the burr. The huge limb let off the cut, hit the tips first, and swung the butt down a full length behind my intended drop zone, straight into the only louvred window I have ever seen (to this day) in Minnesota.
I've kept a lot of lessons with me from that day, the least of which being: thunderf***ers beware!