Reversible computing saves energy by preventing information loss during computation. Since physics requires energy to be released as heat whenever information is erased, preserving information allows computers to operate with far lower energy consumption. This makes reversible computing essential for future low-power and quantum technologies. Modern computers feel smart, but they behave like careless students. They solve problems quickly, then immediately forget how they did it. This forgetting looks harmless, but physics strongly disagrees. Every time a computer deletes information, energy quietly escapes as heat. Reversible computing challenges this wasteful habit by designing calculations that never forget, and that simple change...