What's the hardest part about learning a second language?

In general, the biggest disadvantage is lack of connection to natives. I only regret that I didn't start learning Russian earlier to get a chance to participate in some exchange programme to actually be with the natives and learn the language through them. Sure, you can learn any language by going to a language school but if you don't use it, you can learn it but it is even easier to forget it. But, as I am a very persistent person when it comes to things that I love to do/learn I think I would find a way to speak Russian after I learn enough of it to have a normal conversation.