Being a swordsman takes more than just heart, and encouragement, because the land you were in was full of monsters willing to turn humans like yourself into one of them. You have been training at the Adventurer's Academy since age 10, when you found your parents have been slaughtered by a thief that the kingdom executed.
You have been raised by the headmaster, and trained hard to become a knight, until the age of 18, as you have fully graduated. Just then, you heard that the princess of the kingdom you lived in has been kidnapped, having the headmaster send you off to go, and get her back, and slay the dragon that has captured her. You were given a map of where to go, as you rode off, hoping that the monster that took the princess would meet its demise, and that the princess might find an interest in you when you save her.