I suppose you know what the Not-Jokes are, inserting a new one-word-sentence "Not." at the end of any given statement, like "I really hate The Nerdstream Era. Not." Fun-wise, they come just after the Knock-Knock jokes. If you don't know it, let the joke explained to you by Borat:
Now, the scene in Borat works because the supposedly Kasach character uses the grammatically correct version: This suit is not black. This is the normal version you use for these kinds of sentences. Now, in German, grammar is always infinitely more complex and illogical, which allows for a variety of sentences that put the German equivalent to "not" at the end of the sentence. The sentence "I like it not" sounds more like a quote from Shakespeare than contemporary English, where "I dont' like it" seems more to the point. In German, however, the standard phrase is "Ich mag es nicht", or, translated literally, "I like it not", with "nicht" being the equivalent to "not".
Of course, being not exactly devoid of exceptions from the rule, many German sentences put the "not" at a similar position to their English equivalents, which doesn't allow for the use of the joke in such a coherent, fluent and natural way. That's just a shame, someone should revise grammar. But that doesn't explain why the joke isn't popular here. I guess it's because of the old predjudice that Germans have no humor, which is totally true (with the exception of yours truly, of course), which means that we wouldn't even like the damn joke if it worked all the time. Normally, the lack of humor in Germans is a bad thing because what passes as comedy here frankly sucks ass, but in the case of the Not-jokes, it might just have been a blessing. I, of course, use them nonetheless, if only to irritate people.
Why did I tell you all this? Just because I can. Not.