Click Chemistry: The Certainty of Chance (Nobel Lecture)**

The click chemist's playground: The most important certainty-of-chance outcome of click chemistry was the realization that perfect reactions can exist. Chemistry is about bond-making and bond-breaking reactions between atoms and molecules. So, the emergence of "perfect reaction" status promises to be transformative to the very heart of chemistry, and thence to the range of benefits for mankind that its future evolution may hold.