Every bug needs solving. But also: every bug will _never_ be solved. Why would you think any system or even component should be perfect? Name one perfect system

Every bug needs solving. But also: every bug will _never_ be solved. Why would you think any system or even component should be perfect? Name one perfect system. More simple systems like traffic lights, headlights, tires, brakes,... each of them can fail. Trains can derail, so we should not trust trains?