Being careless is a common behavior that results in various undesirable outcomes. It refers to acting without proper attention to detail or thoughtfulness, which often leads to mistakes, accidents, or missed opportunities. There are many different synonyms for the phrase "being careless," including inattentive, negligent, heedless, thoughtless, reckless, and irresponsible. Inattentive refers to not paying close attention to something, while negligent refers to failing to take proper care of something. Heedless means to act without considering the consequences, while thoughtless refers to a lack of consideration for other people's feelings or needs. Reckless implies a disregard for safety or propriety, and irresponsible suggests a lack of accountability for one's actions.