What?

When I was sturdier I’d talk about how
«Certainly we all will die
We’ll eat shadows, we will bury candles
Die, die, die.»
When I was sturdier I thought
«So what? I am forever mountainous!»
I bravely said, «No death of any kind
Could matter to my mountain mind
Come years, come surging, I am tall!»
When I was «sturdier"I was secretly scared
And the fear was blinding
As you can see, I am no rock
Through mountain wind
What I actually am is thinning clouds