Poverty: You or your family fell on hard times and were unable to pay taxes, resulting in either your character or a family member spending time in prison. Work with your DM to detirmine the details)
Martial training: In adolescence you trained with the weapons of your people and learnt how to use them proficiently (work with your DM to determine details)
During your early adulthood you saved someone's life. This person becomes your companion. (work with your DM to determine details) Roll 1d10 on a 9-10 your companion falls in love with you.