How are Troy and Lyons 'two different people'?

In Act I, Scene I, we see Troy and Bono having a drink and talking about work (the fact that they're close friends is evident in the way Bono feels free to question him about whether or not he's carrying on with another woman). Troy is a hard worker, he provides for his wife, and he does a bit of questioning about why it's so hard to get ahead in his job (only white men get to drive the garbage truck; black men have to pick up the garbage). When Troy's wife Rose appears they banter a bit, and Troy does a little flirting. Then they talk about baseball.

Troy's first love was baseball, and he was an excellent baseball player. The rest of the conversation enlightens the reader that in Troy's day, blacks weren't allowed to play major league baseball. Thus we understand that as good as he was, he never had the opportunity to make it in the big leagues...... he had the talent, but he didn't have the chance.

When his wife speaks about their son Cory, and the college that's recruited him to play football, we hear Troy's bitterness in his response that he'd rather see Cory learning a trade than focusing on sports. He equates Cory with himself, and the loss of his own dream.

But we're talking about the difference between Troy and his son Lyon here, so we'll make note that when Lyon appears Troy alludes to the fact that it's Friday, and his son has come to borrow money. Check, he was right. But was he ? Lyon only asks after his father mentions it, and he asks jokingly.

Troy tells Lyon he needs a job, and he retorts that he works at his music. Troy says his mother has raised him badly; Lyon says his father should have been around. The two are definitely engaging in banter. But unlike his father, you don't perceive that Lyon is bitter about loss of opportunity. He still lives his dream............ and he's unwilling to give up on it. Every clue here gives us the impression that no matter what has happened to Troy (jail), and the fact that he wasn't around while Lyon was being raised hasn't affected Lyon's respect for him. So all in all, from this very long dialog we learn about bitterness and complacency. That's the difference between them.