I speak English as my native language, and my only fluent language, but as a child I had French around me (some cousins and my aunty, as well as my mum being fluent) so I got pretty good at understanding that. I also did three years of French in school, and am in my third year of Spanish, though I'm going to have to take it for another three years after this. As a result of my English, French, Spanish and me loving the history of language (learning roots of words, connections, parent languages etc), I know a lot of Latin too - though I couldn't write or speak it, I can understand most of my friends' homeworks. Through knowing Latin, I can understand most Latin languages to a certain level as well.
I learned Japanese for a little while by teaching myself, but it just didn't seem to sit right in my mind, so I gave it up (though I can still read a little bit and stuff). At my school now, I have several Chinese friends, and by Chinese, I don't mean second or third generation English-speaking Asians. I mean these girls fly from Shanghai/Beijing at the end of every holiday to come to school here, and then fly home at the start of the holidays. Most of them don't speak very good English, so I volunteered to help teach them because I enjoy helping people, and I wanted to see if I could learn Mandarin. Personally, I adore Mandarin - I'm not learning it intensively, because I think I might forget Spanish if I do and I have to remember Spanish for my exams, but Mandarin is such a logical language, especially the writing.
I agree that English is the hardest language to master. It's pretty easy to speak to a usual foreigners' level, but to actually sound fluent? It's hell for my Chinese friends. In Chinese they don't have masculine and feminine differences in spoken (they do in written though), so even the people who hardly sound Chinese anymore still say 'He' instead of 'she' at times. Also, when they are reading things out, they don't know what way to read them, because some words have Germanic roots (shorter, harsher words usually) and some have Latin roots (the ones that relate to French and Spanish more). So words that can look the same, could end up being pronounced completely differently. I'm trying to think of an example of this, but my brain isn't really in full-thinking mode yet. But yeah, the mix of roots of words can make it very difficult for foreigners to read aloud especially :3
part of the fun
of falling in love with you
is the fear you won't fall