The TV show Friends featured a running joke that despite the closeness of the main characters, nobody quite knew what Chandler did for a living. While speculation makes for amusing television, refraining from discussing your job with those around you deprives them of valuable opportunities to get to know you.
This is especially true with kids. While parents may shy away from work-related discussions because they think children won’t understand or will be bored, such talk introduces them to the world beyond school and helps shape their perceptions of adulthood.