As an English as an Additional Language teacher I sometimes speak to people who are convinced that they are not a "language person" and can't learn a new language.
Whilst I definitely agree that some people learn Languages much more easily than others with the right system and lots of hard work anyone can learn a language.
I am a case in point. After 3 or 4 years of consistent study I managed to become a reasonably fluent Vietnamese speaker. It was certainly a challenge but it was great fun and it also gave me a greater appreciation of the struggles my students are going through.