Why is it that we rejoice at a birth and grieve at a funeral? Is it because we're not the person involved?

But remember that for all your pain and gain
Eventually the story ends the same...
You can quite smokin', but you're still gonna die.
Cut out cokin', but you're still gonna die.
Eliminate everything fatty or fried,
And you get real healthy, but you're still gonna die.
Stop drinkin' booze, you're still gonna die.
Stay away from cooze, you're still gonna die.
You can cut out coffee and never get high,
But you're still gonna, still gonna, still gonna die.