Does age affect language learning? I am sure it does for young children, but beyond that I think we can learn languages at any age.
Here is a video by Steve Kaufmann, the person behind The Linguist blog and Lingq, explaining why we should never give up trying to learn a new language however old we are.
There is not a transcript available, but if you activate the CC option on the YouTube screen you will get a fairly accurate transcription of everything Steve says.