OVERREACTING - NO BIG DEAL

Hey, how's it going today? Picture this: your friend finished reading a book last week and he loved it. So two days ago he told you about the book and you asked him if you could borrow the book. He said "Sure! Here it is". So you grabbed the book and then you walked to the nearest bus stop, waited a while and when your bus came, you hopped on.
But here's what happened then: there were no seats available so you just stood near the back exit and you decided to check out your friend's book while riding the bus. That was a bad idea. The bus driver was apparently in a hurry and, at one point, he made a really sharp turn. In that exact moment, you were trying to hold on to the railing with one hand, and trying to turn a page with the other hand. As the driver made the turn, the book just flew off your hand and out the window. Your friend's book? It was gone in one second.
So you got home and first thing you did was, you gave your friend a call and told him what happened.
Now, people react differently to these things, right? Let's talk about two opposite reactions people may have.
The first one would be like this: you call your friend and he says "Oh, no worries. It's not that big a deal." Your friend says this is not that big a deal. When something is not a big deal, that means it's not that important, it doesn't have serious consequences, it's something that can be easily fixed. You know, it's not a serious problem, it's not a big deal, it is not that big a deal.
You know that last sentence - "it's not that big a deal"? This isn't very intuitive for us, Brazilians or Portuguese speakers in general. If we try to translate that literally into Portuguese, we'll end up with something that doesn't make sense. So, don't do that!(não faça isso!!)- for now, just know that "it's not that big a deal" means something like "não é tão sério assim". You can say "This isn't a big deal" or "No big deal" or "It's not that big a deal", for example.
Now, maybe your friend has the opposite reaction. You tell him you lost the book and he goes ballistic. "He goes ballistic" - that means, he gets insanely angry, in Portuguese "ele fica maluco da vida". He starts yelling at you over the phone! And you tell him "Jack, relax! I'm gonna get you a new copy immediately! In fact, I'm gonna get you two copies of that book." But that's not good enough for your friend. He's still mad at you, and you ask him "Don't you think you are overreacting? It was an accident!". Listen again to this question: Don't you think you are overreacting? This is a very common use of the word "overreact". Don't you think you are overreacting?
So, can you guess what overreact means? You think your friend is overreacting. That means that you think he is exaggerating in his anger. You were holding his book and it flew out the bus window. It happens! Why is he that angry? It's not that big a deal. I mean, you would understand if he got a little upset. But he's so mad, he's yelling at you. You think he is totally overreacting. It's just a book, you're gonna go to the bookstore and get him a new copy, or two new copies, like you promised... and, problem solved! Your friend is overreacting. He's too angry for something that isn't that serious, for a problem that isn't that hard to be solved.
And here's something else you could say: "Jack, I think you're blowing this out of proportion". I think you are blowing it out of proportion. I lost your book, I'm gonna buy you a new one and that'll be the end of it! You are angry for no reason. You are blowing this out of proportion! You are blowing this completely out of proportion. So, that happens sometimes, right? Sometimes we see someone blowing something out of proportion. We know it's not a big deal, but that person doesn't and they overreact and blow it completely out of proportion.
Now here's a question for you: have you ever overreacted? Have you ever blown something out of proportion? And then, minutes later you realized that it actually wasn't that big a deal?

Key expressions

it's not that big a deal - it's not a big deal - no big deal: não é grande coisa
overreacting - reagir exageradamente
blow something out of proportion - exagerando demais a um assunto que não é tão sério

Glossary:
you hopped on (the bus) = você subiu (no ônibus)
made a sharp turn = fez uma curva fechada
hold on to the railing = segurar bem no corrimão do ônibus
flew off your hand and out the window = voou da sua mão pra fora da janela
we'll end up with = a gente vai acabar com