This dates back to 1992, when Mattel put out Teen Talk Barbie, whose programmed phrases included “Math class is tough” and “Want to go shopping? Okay, meet me at the mall”. A lot of media attention was given to the negative response the gender stereotype the two phrases illustrated. Ben Zimmer detailed the development of this snowclone on Language Log in March 2006, noting that the Usenet group soc.mtss
made extensive use of it.
Variants of X (as of a Google search today) include i830, irony, dialogue, science, neuroscience, and data synchronization. I find it intriguing that all of these things really are hard in the right context. (Ask a writer whether dialogue is hard!) I know science can be hard to explain to people who don’t understand the scientific method. Many of these snowclones seem intended to open discussion on what actually makes X difficult, using the snowclone to signal that the user is not taking himself too seriously. I am not sure if this is necessarily the prevailing intention of modern users of the snowclone, but it is interesting to note.
So lots of things can fill the X slot; there isn’t a semantic limitation that I can see, other than possibly the aforementioned things-that-are-actually-difficult.
Another Language Log post by Ben Zimmer on this snowclone can be found here.
The Snowclones Database 
In my occasional forays into fiction writing, I always find dialogue dead easy. I should probably become a playwright instead….
Haha, maybe my comment reveals that I am no writer.
Further examples can be found in comments on many stories posted to reddit by http://reddit.com/r/programming/user/consultant_barbie/
@Iain: Fantastic! Thanks.
Blogging is hard, let’s go shopping.
It’s worth noting that this phrase entered most of the public’s consciousness, not as a result of the original Barbie press, but as a result of the Simpsons episode that lampooned the incident using a fictional “Malibu Stacy” doll that Lisa Simpson bought and then became disillusioned with due to its use of phrases like, “math is hard,” and, “let’s put on makeup so boys will like us!”
Shopping is hard, let’s go mountain climbing!