Claude's mother was the one that forced him to battle monsters since he was very young, hoping this would make him get accepted by the holy sword ASAP, the earlier the better. In the end Claude swore to never love another person again after seeing it was his mother's love that destroyed him inside. Also his life's been devoid of meaning, being raised for the sole purpose of being the holy sword carrier. No one ever sought to understand him personally, only seeing him for his status and name.