Fortune knocks once at everyone’s door

Proverbial Meaning: Fortune will come your way at some time so, when it does, you should follow it and seize the opportunity.

Literal Origins: Fortune, or perhaps the personification Fortuna, visits everyone once during their life.

Common Usage: This proverb is not commonly used as written here, but its sentiment is reflected in such phrases as carpe diem - Latin for seize the day.