Idioms are everywhere. You will find them in newspapers, books, magazines, on the radio, on the television, in everyday conversation and at work. Being able to master idioms is almost essential if you want your English to sound more native-like and less awkward. Mastering those tricky idioms will also help you better understand native English speakers (particularly Americans).
Do you ever find that although you consider your English level to be quite good, you sometimes find yourself losing track of a discussion when amongst native English speakers? This may well be because native English speakers tend to speak differently to each other than when they speak with non-native English speakers. The use of idioms and phrasal verbs is commonplace and it can be extremely frustrating to find yourself understanding a conversation or a business negotiation in English to only find yourself flummoxed when a few idioms are introduced into the conversation.
So become familiar with idioms and take your fluency to new heights!