Dave Balderstone responds:

Got out
the "real" lumber and walked over to the miter saw and promptly made the
angle cuts backwards....sigh.

Commiseration. BTDT, and I was talking about *exactly* the same thing
with my neighbor just yesterday, after he told me about cutting a pieve
of crown molding 3/16 too short because he was tired and not paying
attention...

Probably all of us have done it, more than once, and that flies in the face of
not working with machines or edged tools when you're tired. We're lucky when we
only screw up the wood. Most of the scars I carry are the result of being tired
or in a rush, as are most of the project screw-ups (most, not all: there are
some where I outbuilt my knowledge and others where I just made a damned fool
mistake for no good reason except that it was my time to make a damned fool
mistake).

Charlie Self
"A long habit of not thinking a thing wrong gives it a superficial appearance
of being right." Thomas Paine