I recently watched an excellent Russian movie "The Horde" in Russian with English subtitles and got totally confused by one scene in it. The scene is as follows. The Khan tells a European ambassador, "Научись, а то тебя женщина твоя любить не будет." The subtitles say: "Take it. Keep trying. Or your woman will not love you." The context is that just before saying this phrase, the Khan demonstrated his superiority over the ambassador in handing a sword.
I am completely puzzled as to how "научись" can mean "take it and keep trying."
My understanding is that "научись" means "get skilled" (in handling a sword in this context). Let me humbly explain why I think so. The infinitive is "научиться," this is возвратный глагол совершенного вида. The core verb is "учить" ("to teach"), and the postfix "ся" converts it to "учиться" ("to teach oneself," that is, "to learn"). "Учиться" is an imperfective verb, and the prefix "на" makes it perfective, "научиться." Since it is a perfective verb, it means that the process of learning is finished, so the meaning of "научиться" must be "to get skilled," and dictionaries seem to confirm this. "Научись" is the imperative of "научиться" and thus must mean, "Get skilled!" I also checked in the Internet how "научись" is used, and my interpretation seems to fit.
And my interpretation of "научись" makes perfect sense in the context: Get skilled in handling a sword, otherwise your woman won't love you. It makes perfect sense because men who cannot protect their women are to be despised. A weak unskilled samurai deserves contempt.
I am totally puzzled as to what I am missing. Being unable to sort it out on my own, I decided to ask you.
My question is this: How can "научись" mean "take it and keep trying," or did I really spot an inexplicable grieve translation mistake in the movie?