Oh. happy mean;oh centre that can hold!

Enriched with age, we  suffer from the cold,
Yet torrid heat’s   a danger to the heart.
The passion that a youthful one  just moulds
Would kill  some  humans old and over-bold.
Oh.  happy mean;oh centre that can hold!
This will give  us one fine place to start.
Enriched with age,  we  learn to deal with cold
Yet torrid heat  still threatens fragile hearts

Note:

Slouching towards Bethlehem by W B Yeats  has the line,The centre cannot hold