Can I Speak Languages from Every FSI Difficulty Category?

The US Foreign Service Institute sorts languages into five categories based on how long they take English speakers to learn. Spanish and French sit at the easy end, while Mandarin, Japanese, Korean and Arabic land in the hardest group at around 88 weeks. I've spoken languages from almost every category over the years, from Persian and Ukrainian to Turkish and Mandarin. Some felt as hard as the list says, and some didn't. Which category is your target language in?