My first thoughts on reading your topic would be to disagree with the statement given to you. I believe that pride is Lear's flaw in the tragedy. He believes he has power and strength at the beginning of the play-"Come not between the dragon and its wrath" but it is only when he learns humility through his traumatic experiences, that he "sees better" and gains a greater understanding of himself and the world around him. Only after his 'strong spirit" is broken can he (metaphorically) move forward on life's journey. Edmund, Goneril and Reagan, conversely, have "strong human spirits", you could argue, but remain trapped in their bitterness and greed and 'travel" no-where.
Then again, you might look at the word "human" in the topic and argue that the three villains above do not act in a humane way at any stage. Thus Lear needed to learn humility by recognising his humanity-i.e. understanding that he was not above the poor creatures of the Earth. Through this understanding, Lear could travel forward in the "journey of life" and die at the end peacefully.
Essentially, your interpretation will depend, I think, on whether you think Lear has a 'strong human spirit' at some point during the play-where that is and how Shakespeare reveals that to us-and how much this helps him to reconnect with Cordelia, see the truth regarding his other daughters and empathise with the outcasts of society, such as Poor Tom. All the best.