But now at thirty years my hair is grey–
(I wonder what it will be like at forty?
I thought of a peruke the other day–)
My heart is not much greener; and, in short, I
Have squander'd my whole summer while 'twas May,
And feel no more spirit to retort; I
Have spent my life, both interest and principal,
And deem not, what I deem'd, my soul invincible.
No more–no more–Oh! never more on me
The freshness of the heart can fall like dew,
Which out of all the lovely things we see
Extracts emotions beautiful and new;
Hived in our bosoms like the bag o' the bee.
Think'st thou the honey with those objects grew?
Alas! 'twas not in them, but in thy power
To double even the sweetness of a flower.

In these reflective lines from Don Juan, Lord Byron contemplates the ephemeral nature of youth and the inevitability of aging. The imagery of "grey" hair at thirty, and the whimsical thought of wearing a wig, highlight a sense of premature aging. Byron uses the metaphor of squandering "summer while 'twas May" to lament opportunities lost during youth, embodying a regret for not making the most of life's prime. The comparison of life to financial "interest and principal" suggests a depletion of spiritual and emotional resources, once thought "invincible." The imagery of the heart's "freshness" falling like dew evokes the fleeting beauty and novelty of youthful emotions. Byron's musings on whether sweetness is inherent in objects or springs from one's own perception accentuate the power of personal perspective. This passage encapsulates themes of loss, reflection, and the bittersweet passage of time.