Straight razor
Fur is a great boon that evolution gave to mammals. Fur allows the heat conservation required to be efficiently hot blooded and to and to survive in the coldest weather of this planet. For some strange reason, the fur of humans is rather sparse. This lead to an unconscious association between the lack of fur and the superiority of a life form.
As soon as metallurgy allowed decent blades, humans started to alter their fur to look as less as possible like an inferior mammal. Shaving of the facial hairs was already popular among the ancient Greeks. Today we have advanced metalwork technology and it is a daily routine for many to shave. Nevertheless, it seems like it is impossible to make long lasting razor blades. There is a lot of buzz about the technical innovations in new shaving technology and how smooth and how close a shave can get. We sometimes even hear that a new type of blades might last a bit longer.
The sad reality is that the investment on razor blades is constant if not increasing. Those new blades feature patented technology which prevents cheap alternatives and they are sold the price of a lunch each. To motivate us to try those new and improved blades, they even inflate the price on the old types of blades. The net effect is that we keep using the same blade as long as possible with disastrous consequences for our poor skin.