Use 'foible' to describe minor character weaknesses that everyone has, making someone more relatable or human. Every hero has their foibles, even Superman is overly trusting at times.
Pro Tip 2/3
Not Offensive
'Foible' implies patience or tolerance for someone's weaknesses, it's not used to harshly criticize. She laughs about her foibles, like her love for outdated slang.
Pro Tip 3/3
Positive Angle
Discussions of foibles often come with a tone of fondness or amusement, not serious concern. His forgetfulness was just another one of his foibles we'd come to adore.