Burning Candles at Both Ends - A Good Thing or Not?

I was looking through a musty old poetry book and discovered this familiar piece by Edna St. Vincent Millay:

My candle burns at both ends
It will not last the night
But ah, my foes, and oh, my friends —
It gives a lovely light!

Then comes a second from her which is a little less well-known:

SAFE upon the solid rock the ugly houses stand:
Come and see my shining palace built upon the sand!

My question is, why are these two poems called “First Fig” and “Second Fig”? And, the second poem is more than obviously a swipe at the Bible. Maybe the first is too.

I do know that in some quarters, the fig is thought to be the “Forbidden Fruit”. That would seem likely because the fig is very Mediterranean. It more than occurs that the first fig could have referred to sexuality (which many of you would rather I not refer to at all), since many misinformed interpret the Forbidden Fruit to refer to sexual sin between Adam and Eve. That would then make the second fig, avarice perhaps?

Since these poems were written during the “Roaring Twenties”, it’s likely they did refer to the excesses of those days. But I’m going to climb into my little comfort zone and prefer the first, at least, to mean to live life to its fullest. What can be wrong with that? God certainly made our world a beautiful place and gave us one life to live. Doesn’t he want us to love our lives as fully and beautifully as we can? Creating as much light as we can can't be all bad. Just thinking.