I will say that just about everything in this chapter was satisfying for the most part. I enjoyed Billy's speech, though I agree with @BlindAmbition that there could have been a little more to it. Otherwise, I really enjoyed it. I also appreciated that Billy finally figured out a few things, like actually talking to at least Brett. He didn't keep it all a secret from everybody and actually confided what happened to him. However, I was extremely disappointed that he didn't learn his lesson after all and proceeded to keep the blackmail a secret from Dustin, and it turned out that Dustin already knew about it. It just bugs me that he let Hartley get away with that and rolled over and took it. It's the end of the story and Billy still hasn't progressed to a point where I have more confidence in him. Well, not entirely, but maybe this will finally teach him?
Jack and Jen, everyone else has stated this clearly, but they are disgusting people. Thankfully Joey's mom is finally ending the charade. Jack is Jack, and I think he's finally been uncovered for the hypocritical asshole he's always been. Jen though, is truly disgusting. It really seems like she doesn't give a damn about her own son. I just don't get it. They kept this ridiculous lie going for Brett's entire life, while she lied and manipulated both Billy and Brett, and yet there they were doing their thing behind closed doors all that time. Why didn't they just tell the kid the truth already? What was the point of maintaining the lie for so long? Too bad George didn't tell earlier and put Billy out of his misery. Oh well, that line in the letter made me laugh though. I really loved George as a character, and I missed him a little myself.
The way this chapter was written brought back so many memories of the end of my time in high school, just a few years before this was set. Though I will say, interestingly enough that while the last day did indeed feel like a waste of time, we actually had a final exam the same exact day as our graduation. It was very unusual. I'm the youngest of five kids in my family and we all graduated from that same high school two years apart. So I was aware of how it worked for all the older kids. Just two years previous, when my sister graduated, the last day of school and final exams was the day before the graduation ceremony, and there wasn't any school on commencement day. Yet for whatever reason, two years later they had changed the scheduling and such, and so we actually had our graduation ceremony the evening after the last day of school. So, it was pretty strange to take a test, and realized that it didn't even matter how well we did on it at that point, because of how the law worked, we would have already had to be told if we were going to pass or fail that class. I think I did fine on that test though.
Anyway, I appreciated how you wrote this. It had me smiling, I actually held my diploma aloft like Link as well as I hopped down the stairs from the stage. I was so glad it was over as well.