The experience is quite common in dreams , daydreams, and memories , where we quite often take the external perspective. Some people experience an OBE while under the influence of an anesthetic or while semi-conscious due to trauma.
Some people have an OBE while under the influence of drugs.
Finally, some people experience an OBE when they are near death. Susan Blackmore, a parapsychologist with heavy skeptical leanings, is considered one of the world's leading authorities on OBEs and NDEs. She had an OBE while attending Oxford during the early 1970s. During her first year at Oxford she had an OBE while stoned on marijuana after several hours on the Ouija board . The experience also occurred during a period of her life when sleep deprivation was common for her.