Your bobbin thread is sentient. It holds a grudge. It knows what you did last summer. It will take its revenge by running out just as you reach the centermost topstitching on the two-year project you’ve been working on for your perfectionist mother-in-law who, by rights, shouldn’t have vision that perfect at her age anyway.
It will laugh at you.
Just don’t retaliate because the sewing needles will return fire. If they can’t skewer you they’ll throw themselves across the train tracks. You know. For the Gipper.