تعريف ومعنى "fortune knocks once at every man's door"

What is the origin of the proverb "fortune knocks once at every man's door" and when to use it?

The origin of the proverb "fortune knocks once at every man's door" is often linked to European folklore, with various versions appearing over time. The saying reflects the belief that opportunities for success or fortune are rare and should be seized when they arise. It serves as a reminder that life is unpredictable, and waiting for luck to strike more than once may not always be wise. One should be prepared to act whenever an opportunity presents itself.