Confounding to learning language, on top of one's base ability to do do in general, are the teaching methods not meshing at all with the individual. For me, rote memorization of anything is nearly impossible, doubly so if the thing to be memorized has no immediate utility. "Conversational" language learning and similar that give you a bunch of vocabulary and bring in the grammar later are why I failed Spanish 1 three times. I need the grammar first, then words with etymology. It also helps to not fight with phonetic collisions between different languages using their own bastardization of Latin script, which is why I was far more easily able to meet my college language requirement by teaching myself classical Greek and translating the things I thought were interesting.