Pink co-wrote her song ‘Who Knew’ about a friend who she discovered passed away from a drug overdose when she was 14. She said it could also be about the death of a friendship. Source: SongFacts

Lyrics

You took my hand
You showed me how
You promised me you’d be around
Uh huhThat’s right
I took your words
And I believed
In everythingYou said to me
Yeah huh
That’s rightIf someone said three years from now
You’d be long gone
I’d stand up and punch them out
‘Cause they’re all wrongI know better
‘Cause you said forever
And ever
Who knewRemember when we were such fools
And so convinced and just too cool
Oh no
No noI wish I could touch you again
I wish I could still call you friendI’d give anything When someone said count your blessings nowFor they’re long gone
I guess I just didn’t know how
I was all wrongThey knew better
Still you said forever
And ever
Who knewYeah yeahI’ll keep you locked in my head
Until we meet again
Until weUntil we meet again
And I won’t forget you my friend
What happenedIf someone said three years from now
You’d be long gone
I’d stand up and punch them out
‘Cause they’re all wrong andThat last kiss
I’ll cherish
Until we meet again
And time makesIt harder
I wish I could remember
But I keep
Your memoryYou visit me in my sleep
My darling
Who knew
My darlingMy darling
Who knew
My darling
I miss youMy darling
Who knew
Who knew———————————————————————Songwriters: Alecia Moore / Lukasz Gottwald / Max MartinWho Knew lyrics © Kobalt Music Publishing Ltd., Sony/ATV Music Publishing LLC