How does the narrator describe his younger self? What is he implying with these descriptions?

Though changed, no doubt, from what I was when I first came among these hills; win like a roe I bounded o’er the mountains, by the sides of the deep rivers, and the lonely streams

("Tintern Abbey")

The narrator describes his younger self as:

Immature, inexperienced, and a loser.

What he implies with these descriptions is that his change came after he lived this experience in the mountains. That it allowed him or her to grow, become a winner, and an experienced person.

Explanation:

The reasons behind these answers are: First, he or she calls himself or herself a changed person. Meaning that before what he or she is about to narrate made him change. Also, he or she also says that only after coming to these hills he or she was able to win. Therefore, he or she needed to live these experiences to become a winner. Furthermore, going through all these scenarios was the factor that made him or her grow.