lyrics of "I'll be there for you" (The Rembrandts)
(FRIENDS Soundtrack)


So no one told you life was gonna be this way
Your job's a joke, you're broke, your love life's D.O.A.
It's like you're always stuck in second gear
When it hasn't been your day, your week, your month, or even
your year, but

{Chorus}

I'll be there for you
When the rain starts to pour
I'll be there for you
Like I've been there before
I'll be there for you
'Cause you're there for me too

You're still in bed at ten and work began at eight
You've burned your breakfast so far, things are going great
Your mama warned you there'd be days like these
But she didn't tell you when the world has brought you down to your knees, and

{Chorus}

No one could ever know me
No one could ever see me
Since you're the only one who knows what it's like to be me
Someone to face the day with
Make it through all the best with
Someone who always laughs at
Even when I'm at my worst, I'm best with you
Yeah!

{Chorus}

I'll be there for you
I'll be there for you
I'll be there for you
'Cause you're there for me too

I don't need a perfect translation. I'd just like to grasp the meaning of it.
Is this an expression people really use?