Also, metamemory in psychology means an individual's knowledge about whether or not they would remember something if they concentrated on recalling it. The modern sense of "an X about X" has given rise to concepts like "meta-cognition" (i.e. cognition about cognition), "meta-emotion" (i.e. emotion about emotion), "meta-discussion" (i.e. discussion about discussion), "meta-joke" (i.e. joke about jokes), and "metaprogramming" (i.e. writing programs that manipulate programs).