While Rockie was sobbing, he screamed at Edward, talking about how always thinking of the negative is as problematic as only thinking about the positive, saying that Edward will follow up on a path of a hero and forget about him, while he'll stay stuck with his ordinary every day stupid life, he'll study, work, and die, while Edward will be able to get more than Rockie will ever be able to, working like a slave in a dumb job while Edward has the opportunity to have fun and be happy because he is doing something for society.
Edward was out of words, he was mad, he didn't like Rockie's attitude, but, he did not want to upset Rockie more, he says that he will never forget Rockie, he is his best friend, one of the first friends that he ever had.
Rockie calms a bit down and replies, saying that Edward is practically his only friend, the only other friends he has, he got because of Edward, because they knew Edward they decided to be friendly with him, but Edward is the only real friend he has, if Edward goes always, everyone else will go with him, and Rockie would feel alone.
After a bit of silence, Edward speaks up, he calmly explains that Rockie was overreacting, and that everything would be fine, and says that what Rockie said, already says enough, 'best friend', how will Edward forget someone, that he considers a best friend? And Rockie goes quiet, bue he then says that he's sorry, and he probably indeed overreacted a bit, so he asks for one thing, a promise.
Rockie pulls up his hand, and asks Edward to promise him, that no matter what they will always be friends, and Edward pulls his hand up as well, and shakes Rockie's hand, and says "I promise".