Why did Cole say that on the island he "realized I was dying and I had never really even lived yet"?

Explanation:

The statement made by cole on the island could be seen as a reflection of someone in deep thought with fading hopes and despondency. With so much in one's wishlist, aims and aspirations but with very little or almost no notable achievement. Cole reflected on his past and realized he has not done much for himself spending most of his useful lifetime in a detention center, as much as he tried, he also hasn't had a positive impact on the life others and therefore looked down on himself as almost useless as there is no notable achievement or accomplishment made over time.