fact of life

American  

noun

1. any aspect of human existence that must be acknowledged or regarded as unalterable.

   Old age is a fact of life.

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idioms

1. facts of life, the facts concerning sex, reproduction, and birth.

   to teach children the facts of life.

Etymology

Origin of fact of life

First recorded in 1850–55

Example Sentences

Insecure housing and seasonal wages are a fact of life in St Ives.

From BBC

Most analysts think that e-bike and e-scooter schemes are here to stay - and local skirmishes over how they are parked may simply become a fact of life.

From BBC

“It’s just the way it is. It’s a fact of life.”

From Los Angeles Times

He lives in a "hacker-house", a shared living and workspace, where he and his colleagues continually swap ideas, and believes working long hours is just a fact of life.

From BBC

Despite leaning old in years, it’s a coalition marked by an immature inability to accept a basic fact of life: that the kids today aren’t going to like the same stuff you enjoyed as a kid.

From Salon