One thing that always annoys me on language learner forums is when people say they learned X language in (fairly short amount of time) but never list what sort of advantages they had going in. So for example, someone will say “I reached the N1 level (highest classification of Japanese understanding on the JLPT exam) in 3 years!” but what they won’t tell you is that they studied abroad in Japan for a year, or they had previous working knowledge of Korean (which is grammatically similar) or Mandarin Chinese (Which will give you a leg up on Kanji because of Hanzi) or that they had a huge amount of free time to study. These little advantages add up. People sometimes omit these advantages either because they don’t realize they have them or they wanna look more impressive to their peers. 

Anyway, for those learning another language, don’t feel bad if someone gets there faster. Fluency is a vague and nebulous term to begin with anyway. Not only is it not a race, but you don’t know what advantages someone had going in.