What does it feel like to be able to understand and communicate in a foreign language?

I've been studying other languages since I was 8 and now I speak 5 languages, yet English is the only one where I feel completely fluent.<br><br>I've had the feeling of being able to understand and communicate fluently in English for at least 13 years, yet in every other language I've learned the best I've felt was "partially fluent", and this only lasted for a few years, after which I lost all my fluency.<br><br>I'm interested in knowing how it feels to be able to understand and communicate in a foreign language, whether it's Spanish, French, German, Italian, Portuguese, Swedish, Danish, Dutch, Russian, Arabic, Chinese, Japanese, Korean, Hindi, etc.<br><br>How does it feel to be able to understand and communicate in a language that is completely different from your native language?