Though “Last Week Tonight” was on hiatus this week, John Oliver covered the most important news event of the week (fireworks, of course!) in a Web exclusive posted to the show’s YouTube page. If you’re an adult who enthusiastically participates in the fanfare around fireworks — the crowds, the classical music, the terrible parking spots — then you might not want to watch Oliver’s cynical take on the yearly ritual that demonstrates “the ability [Americans have] to wholeheartedly embrace excitement while letting disappointment and failure slip away as quickly as you can.” Oliver then did his best impression of a firework. It was pretty good.