Never lend your tools to anyone, boy.
My dad had a job working for a carpet cleaning company in his early 20's. Driving a cargo van, he quickly tired of all the equipment rattling around in the back. Recognizing the problem, my dad did what was natural: headed to the local home improvement store, picked up some lumber and a circular saw and got to work on building an organizer.
After a weekend, the organizer was a success. It took that rattling cargo van and gave everything a place. It worked so well that his boss saw it and wanted to build himself one. The boss just needed to borrow my dad's circular saw.
After an agonizing week, the boss handed back the saw. Then he handed back the power cord, separately. While sawing a 2x4, the power cord got in the way. Not to be deterred, the boss powered through...the cord. While handing it back, he offered my dad some confident advice: "some electrical tape is all you need, it'll work fine."
Just one project and one lending after purchasing, the saw was junk. It would be taped, and it would sort of work, but the bulge from the electrical tape meant that it would hang on boards and be a general disaster to use.