Why should we care about informal Indonesian language? Isn’t this the silly stuff of teenagers? Shouldn’t foreigners adhere to the elegant, dignified formal Indonesian language? Many Indonesian-speaking visitors can’t understand the slangy everyday Indonesian. They speak what they learned in class or books, but they fail to connect with Indonesians because they’re too baku—too stiff. Being stiff is an especially fatal flaw in the nimble, goofy, gregarious Indonesian culture. The best antidote to being stiff is mastering the informal Indonesian language. This book is to let visitors make deeper connections with Indonesia. Too often the foreigners get frustrated by the thick slang and then retreat to their expat bubble. Indonesians also could realize how their colloquial language can be unintelligible even to the most earnest Indonesian language learner. Perhaps after reading this book, slang-throwing Indonesians will have some mercy on the bule (foreigner) and learners of bahasa come to embrace the adventures of speaking everyday Indonesian.