What does only today I wish I didn't have only eleven years rattling inside me like in a tin can?

This line reflects a sense of frustration and confinement, suggesting that the speaker feels limited by their age and experiences. The imagery of "rattling inside me like in a tin can" evokes a feeling of being trapped or noisy with unfulfilled potential. It conveys a longing for maturity or a desire to break free from the constraints associated with being young. Overall, it captures the tension between youthful innocence and the yearning for greater freedom and understanding.