Answer:
The correct answer is option 1) They explain how unaware the speaker is that the innocence of childhood is fleeting.
Step-by-step explanation:
Explicitly the author says that he went his way without paying attention. (I ran my heedless ways)
That is to say, he continued to grow and leave his childhood behind without realizing it, because he was so happy at that moment that he did not perceive when he had stopped being young.
In this poem the author recounts all his childhood as a pleasant moment and with happy memories. But giving indications that this happiness will end.
He continues throughout the poem recounting all his experiences lived in such detail, that at the end of the poem he repeats the phrase "Nothing I cared", another sign that indicates that he was naive to be aware of the passage of time. And now he shows great regret because those magical days will no longer return.