Such is life
An acceptance of the unpredictable fortunes of existence, often spoken with an air of weary resignation.
The early uses of this phrase date from the mid 18th century; for example, Joseph Baretti's A Grammar of the Italian Language, 1762, translates "Cosi va'l mondo!" as "Such is life" and continues:
"Such is life, that whatever is proposed, it is much easier to find reasons for rejecting than embracing."
'Such is life', of course, mirrors the French 'C'est la vie', which equates to the English 'that's life', or 'life's like that'. Modern variants are 'that's the way it goes', 'that's the way the ball bounces', 'that's the way the cookie crumbles' etc.