An adventure is an exciting experience or undertaking that is typically bold, sometimes risky. Adventures may be activities with danger such as traveling, exploring, skydiving, mountain climbing, scuba diving, river rafting, or other extreme sports. Adventures are often undertaken to create psychological arousal or in order to achieve a greater goal, such as the pursuit of knowledge that can only be obtained by such activities. Motivation Adventurous experiences create psychological arousal, which can be interpreted as negative (e.g. fear) or positive (e.g. flow). For some people, adventure becomes a major pursuit in and of itself. According to adventurer André Malraux, in his Man's Fate (1933), "If a man is not ready to risk his life, where is his dignity?". Similarly, Helen Keller stated that "Life is either a daring adventure or nothing." Outdoor adventurous activities are typically undertaken for the purposes of recreation or excitement: examples are adventure racing and adventure tourism. Adventurous activities can also lead to gains in knowledge, such as those undertaken by explorers and pioneers – the British adventurer Jason Lewis, for example, uses adventures to draw global sustainability lessons from living within finite environmental constraints on expeditions to share with schoolchildren. Adventure education intentionally uses challenging experiences for learning. Author Jon Levy suggests that an experience should meet several criteria to be considered an adventure: Be remarkable—that is, worth talking about Involve adversity or perceived risk Bring about personal growth. Mythology and fiction Some of the oldest and most widespread stories in the world are stories of adventure, such as Homer's Odyssey. The knight errant was the form the "adventure seeker" character took in the Late Middle Ages. Adventure fiction exhibits these "protagonist on adventurous journey" characteristics, as do many popular feature films, such as Star Wars and Raiders of the Lost Ark. Outdoors Adventure books may have the theme of the hero or main character going to face the wilderness or Mother Nature. Examples include books such as Hatchet or My Side of the Mountain. These books are less about "questing", such as in mythology or other adventure novels, but more about surviving on their own, living off the land, gaining new experiences, and becoming closer to the natural world. Questing Many adventures are based on the idea of a quest: the hero goes off in pursuit of a reward, whether it be a skill, prize, treasure, or perhaps the safety of a person.