Tiny pieces of thin wire suck. They can be pretty much flush with the tire and virtually non detectible, but protrude enough when the tire is inflated, and a load put on it, to the protrude enough to puncture the new tube.
Taking the tire completey off and turning it inside out can help in detecting it.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.