"I don't feel like it."
Translation:Ich habe keine Lust.
Reported "Mir ist nicht danach." today—2019/06/09.
As I stop and think about it, I feel that "Mir ist nicht danach." is actually a better translation for "I don't feel like it." than "Ich habe keine Lust." or the equivalent (but more colloquial) "(Ich hab') kein' Bock" which I'd rather translate to "I can't be bothered." and (in B.E.) "I can't be arsed." respectively.
The reason why I say this is that you can say "Ich habe kein/e Bock/Lust." bzw. "I can't be bothered/arsed." without any context and people will understand that you are feeling generally lethargic and unwilling to do anything productive; whereas "Mir ist nicht danach." bzw. "I don't feel like it." has to refer to a specific task or activity; you can't just open a conversation with "Mir ist nicht danach."/"I don't feel like it." and not expect follow up questions.
At least, that's been my experience with these phrases.
I thought danach meant after that.
Well... it means nach das. But nach can mean all sorts of things.
Mir ist nach einem Stück Kuchen does not mean "To me is after a piece of cake".
Instead, it means "I feel like a piece of cake." Except, you know, not literally. You don't feel as if you yourself are a piece of cake, but rather, you're a bit peckish and you think a piece of cake would be just the thing right now.
Similarly, Wonach steht dir der Sinn? does not mean "After what stands to you the sense?"
It means something like "What do you feel like?"
In another exercise, the phrase to translate is: "No, I do not feel like it."
Both 'Nein, mir ist nicht danach" and "Nein, ich habe keine Lust dazu." are accepted answers. But here, if you drop the "Nein", BOTH are rejected for "I don't feel like it." Reported both.
The phrase here should have been "I don't feel like being consistent."
ich habe keine Lust (capital L!) is fairly direct, and as such, not particularly polite.
Mir ist nicht danach is a bit more polite but still says that you don't want to do that; even more polite would be Das würde ich lieber nicht tun "I would rather not do that" which doesn't say explicitly that you don't want to do it but just says that you would prefer not doing it and by saying so, merely implies that you don't want to. Or simply Nein danke "No, thank you" or Nein danke, lieber nicht "No thank you, I'd rather not" or Nein danke, ich habe schon andere Pläne für heute "No thank you; I already have other plans for today" etc.
But that gets into the tricky parts of interpersonal etiquette and social "dancing" around saying no, so there's no one best answer.
(How much easier it would be if we could just be direct! "No, I don't want to.")
That said, if you do want to be explicitly rude, then Kein Bock. would be even more rude than Ich habe keine Lust.