My favorite Teasdale poems were her most depressing, and I considered the best of them all one entitled "The Long Hill" (1919):
I must have passed the crest a while ago
And now I am going down.
Strange to have crossed the crest and not to know--
But the brambles were always catching the hem of my gown.
All the morning I thought how proud it would be
To stand there straight as a queen--
Wrapped in the wind and the sun, with the world under me.
But the air was dull, there was little I could have seen.
It was nearly level along the beaten track
And the brambles caught in my gown--
But it’s no use now to think of turning back,
The rest of the way will be only going down.
It's true that we feel young until one day we wake up and realize that this is no longer the case, that our earthly lives are 50%, 60%, 70% or more behind us. But Teasdale was a bit young to have recorded such thoughts; she was only 35 years old when it was published. By the world's standards, she was also a bit too successful to have been so down on her life, having been married in 1914 and having just won, in 1918, a Pulitzer Prize for her poetry.
But as they say, you're as old as you feel, and apparently having no eternal hope makes one feel ancient at an age most would consider a prelude to one's prime. I have been unable to find any record of Teasdale having found everlasting life.
And in point of fact, she was on her way down by the time she published "The Long Hill"; she overdosed on sleeping pills in 1933, dying at the age of 48.
That's one way to avoid the inevitable deterioration of old age, I suppose.
But there's another, infinitely better way -- and that is to join the apostle Paul in saying, "Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal." (2 Corinthians 4:16-18)
The fact is, it's possible for us to know with absolute certainty, whether we're 30 or 70 or 110, that the best is yet to come. It's a free gift. And it's available to anyone willing to bow the heart to our Creator.