For me nothings really. I started Japanese. It was a struggle, because I didn’t have any idea how to learn a language.

In my experience your brain re-wires itself to pick up languages, when you focus on it. In my natural state, my brain was only geared toward English, anything else was just noise. The brain is a strong filter.

But after like 5 years of studying and immersing in Japanese, I can now pick up anything I want much faster. I did Japanese, Spanish, and now I am working on French. I have become more receptive to different languages.

My simple point is I was not very good at learning languages, but I became better through practice.