The concept of personal space and its different levels, including intimate space, personal space, social space, and public space, are like invisible bubbles that humans and even animals have. Psychologist Edward Hall first made this distinction in his book 'The Hidden Dimension' in 1966. Personal space is typically about three feet, and it varies depending on the person. A personal story is shared about a roommate who was an extreme close talker, highlighting the importance of personal space.