The frequency-hopping technique behind Wi-Fi, Bluetooth and GPS was co-invented by Hedy Lamarr. The windscreen wiper was patented by Mary Anderson. Both are used by billions of people. Neither inventor captured much of the value.
What actually went wrong
In several of these cases the patent existed but expired before the technology became commercially viable. In others the invention was disclosed publicly before filing, which destroys novelty. In others the rights were assigned away for very little because the inventor had no idea what they were worth.
The pattern is not primarily about the quality of the invention. It is about the paperwork, the timing and the negotiation.
Three rules that still apply
File before you disclose. A patent requires absolute novelty. A trade show, a pitch deck sent without an NDA or a social post can defeat your own application.
Know what you are signing. An assignment or an employment clause can transfer the whole invention. Read it before, not after.
Protect the brand as well as the technology. Patents expire in twenty years. A trademark, renewed and used, can last indefinitely, which is why the names outlive the inventions.
What protecting an invention requires today
The recurring reason inventions were lost was not the quality of the idea but the absence of a filing in the inventor name. The rules that decide it now are narrow and unforgiving.
Novelty comes first: showing the invention at a fair, publishing it or demonstrating it without a confidentiality agreement can destroy patentability before anything is filed. File, then disclose.
Then the term. A patent lasts twenty years from the recognised filing date, non-extendable and subject to annuities (article 53 of the Mexican Industrial Property Law). A utility model, which fits improvements to the shape or arrangement of a device, lasts fifteen (article 62). Neither renews. And a granted patent that stops paying its annuities lapses well before its term is up, which is still one of the commonest ways rights are lost.