Brendan Gahan wanted to work in advertising when he was a kid. The co-founder and CEO of LinkedIn influencer marketing agency Creator Authority—featured in the latest episode of video series Resume Rewind, sponsored by entertainment wiki hosting service Fandom—had an uncle who was a creative director at Wieden+Kennedy.Gahan’s first job was at a Sweet Factory candy store in a mall, but his first interview at an ad agency stood out to him. “I remember thinking, ‘There’s no way this is an office.’ How do people get work done here? Open…