To learn/ understand things around us so that we can apply the knowledge and skills acquired to progress even further.. in the domains we like to progress in.
explanation: Early man learnt to create fire though by an accident , that was an experience, He learnt from his experience. If you are an early man even today, you can learn ONLY by experiences. but today, as the world has become complex, learning solely through experiences will limit the quantity of things you learnt making you unfit to survive in this complex world.
so.. You learn by reading stuff ( studying) missing the fun and more intense type of learning experiencing.
simple ans= to live, you have to do something, to do , you have to know something, you study to know something, so that u can do something to live.