You try to grab the dog′s collar but instead the end of your finger intersects the key ring holding the dog tags at just the right position to drive the end of the key ring under your fingernail all the way to the little half-moon.
Candy bars wrapped with industrial-strength mylar, making them so difficult to open that most of the caramel ends up on your shirt.
You discover that someone has been using your wood chisel to open paint cans.
You realize that the reason the dog has been so quiet is that he has found a box of Kleenex.
When you are working on a carburetor, and a spring comes flying out a hole, launching a little part into the air, which you definitely hear landing somewhere in the grass behind you.
Parallel parking on a steep hill and then discovering that the parking meter is out of order.
Wrapping all of your Christmas gifts, then by the time you buy the tags, you have forgotten what is inside each package, so you need to open a few to make sure they are given to the correct recipients.