Learning is the process of acquiring new, or modifying existing, knowledge , behaviors , skills , values , or preferences . The ability to learn is possessed by humans, animals, and some machines ; there is also evidence for some kind of learning in some plants. Some learning is immediate, induced by a single event (e.g. being burned by a hot stove), but much skill and knowledge accumulates from repeated experiences. The changes induced by learning often last a lifetime, and it is hard to distinguish learned material that seems to be "lost" from that which cannot be retrieved.