Chance led to the most important discoveries.. Facts stranger than fiction

The famous American scientist Albert Gregory never tired of repeating a saying he believed in. It was one sentence that read: "Discovery is nothing but the meeting of chance with an attentive, attentive and ready mind."
This saying is completely true, as this is exactly what happened with many scientists. Although scientific discoveries come after diligent research attempts, strenuous efforts, and long work to reach a specific result, sometimes coincidences or some accidents lead to a fateful and important change that leads to important discoveries in human history. How many coincidences have generated discoveries that have benefited humanity.