#foreign languages

I've been studying Japanese for a while now and I think its grammar is pretty tough. But I'm wondering if there's another language out there that's even more complex. I've heard some people say that languages like Arabic or Russian have really complicated grammar systems, but I'm not sure. Can anyone who's studied these languages chime in and give me their take? I'm looking for something that'll really challenge me.

I've been thinking about language learning a lot lately and I'm convinced that most methods are a waste of time. I mean, how many people actually become fluent in a language through those boring language courses or apps? I've met very few people who can hold a conversation in a language they 'learned' through these methods. What's worse is that people are often too afraid to speak and make mistakes, so they end up stuck. My friend's mom spent years 'studying' French and still can't string together a basic sentence. I'd love to hear from people who've actually had success with language learning - what's your secret?