The adventure's the thing; the hurt and anguish of Aunt Sally, the pain and discomfort of Jim, these never occur to him.
But Huck, involved in real adventures, is continually bothered by his conscience.
All during the raft ride down river, he tries to answer the question whether he's doing right by the Widow's sister and by Jim, or not.
The preoccupation with justice has him on the horns of a dilemma. He's wronging Jim if he returns him to slavery; he's wronging Miss Watson if he helps Jim escape.
Huckleberry Finn goes through some changes and learns some life lessons throughout his journey.
Huck changes from being just an immature boy at the beginning of the novel to being a more mature man who looks at things in a different perspective now.
Huck has no way of knowing what is right because he has no role model in Tom, his hero. He is a realist, and generally level-headed except when he goes off after Tom Sawyer's adventure, or when he follows Tom's lead.
He is not "civilization." The end of the book makes this clear.
During their adventures, Huck and Tom find a box of gold.
Soon after, Huck recognises footprints in the snow as his father's and he realised that Pa has returned to claim Huck Finn's money that he found after defeating Injun Joe....