Didier Pittet has been the champion of hand hygiene. With the COVID-19 pandemic, his slogan “Adapt to Adopt” provoked a previously unimaginable response. In just a few weeks, everyone from perfume and wine makers to city pharmacists started to produce alcohol-based handrub, while YouTubers and humorists promoted its use. Heralds of the Adapt to Adopt strategy, they got creative in order to encourage hand hygiene on a mass scale. But reluctance, misunderstandings, and false ideas still subsist. Following on from *Clean Hands Save Lives*, this book explains why hand hygiene remains our primary weapon against epidemics, why alcohol is effective, why alcohol-based handrubs and gels are not dangerous, and why their distribution as a common good for humanity could become a model for global health, or even society in general. When we adapt, we feel invested, concerned, and involved. Nothing matters more for hand hygiene, which protects us and protects others.