After I first started running and losing some weight, I became enthusiastic about it. Then with the notions of 'more is better' and 'no pain, no gain', I cranked up the mileage and pushed through the pain. But I learned a hard lesson when I tore a calf muscle.
Since then I've learned that form and technique, consistent and gradually harder practice, and getting expert help are necessary to really learn something. Ten years later, and over 18k miles logged, I can say I know how to run.