I'm calling BS on this, sorry! I learnt my second language at over 21. I'm learning a third one right now. I have no problem with languages. Accents you work on if you have the time.
I learnt progamming at over 30. The PC came on the market when I was over 30... I'm still learning. It depends on the individual. Some people can, others can't.
If I had stuck with what Iearned before 14 I would be a sheep farmer. That was all there was in my neck of the woods.