"I grew up afraid of humans and my days were spent studying, mostly. I became a sellsword the day I was revealed as a charlatan." I picked an Elf in the first step so being afraid of humans might come from the Elven group this character is part of living in an area with lots of humans - maybe in the fallen Kinsguard regions where some of the humans may have become robbers in order to survive. An experience where this character's Elven group became victim of the human robbers might've driven him to shy away from violence and try to find another path in life, so he began to study rigorously without really having the knack for it. Despite his best efforts he just couldn't become whatever he was studying for and would end up compensating by posing as an expert. Eventually he was outed and he was forced to face the fact that he was a fighter by nature and would have to face his deep set fears.