Fun is the enjoyment of pleasure, particularly in leisure activities. Fun is an experience — short-term, often unexpected, informal, not cerebral and generally purposeless. It is an enjoyable distraction, diverting the mind and body from any serious task or contributing an extra dimension to it. Although particularly associated with recreation and play, fun may be encountered during work, social functions, and even seemingly mundane activities of daily living. It may often have little to no logical basis, and opinions on whether or not an activity is fun may differ. A distinction between enjoyment and fun is difficult but possible to articulate, fun being a more spontaneous, playful, or active event. There are psychological and physiological implications to the experience of fun.
The way the word "fun" is used demonstrates its distinctive elusiveness. Expressions such as "Have fun!" and "That was fun!" indicate that fun is pleasant, personal, and to some extent unpredictable. Expressions such as "I was making fun of myself" convey the sense that fun is something that can be amusing and not to be taken seriously. The adjective "funny" has two meanings which often need to be clarified between a speaker and listener. One meaning is "amusing, jocular, droll" and the other meaning is "odd, quirky, peculiar". These differences indicate the evanescent and experiential nature of fun and the difficulty of distinguishing "fun" from "enjoyment".
Fun's evanescence can be seen when an activity regarded as fun becomes goal-oriented. Many physical activities and individual sports are regarded as fun until the participant seeks to win a competition, at which point, much of the fun may disappear as the individual's focus tightens. Surfing is an example. If you are a "mellow soul" (not in a competition or engaging in extreme sport) "once you're riding waves, you're guaranteed to be having ... fun".
The pleasure of fun can be seen by the numerous efforts to harness its positive associations. For example, there are many books on serious subjects, about skills such as music, mathematics and languages, normally quite difficult to master, which have "fun" added to the title.