The does until the don’ts

This is how it works
You're young until you're not
You love until you don't
You try until you can't
You laugh until you cry
You cry until you laugh
And everyone must breathe
Until their dying breath
No, this is how it works
You peer inside yourself
You take the things you like
And try to love the things you took
And then you take that love you made
And stick it into some
Someone else's heart
Pumping someone else's blood
And walking arm in arm
You hope it don't get harmed
But even if it does
You'll just do it all again.