Reading and writing fill in the blanks
Characters that lack internal conflict or multiple facets to their personality are often as flat or one-dimensional characters. This is often seen as a bad thing in a story, especially for first-time writers, when all of the characters are one-dimensional. However, if there are one or two characters that are simplistic in nature for a reason, it may not be perceived as a negative . As long as an author uses one-dimensional characters correctly, and with deliberate intention, there is nothing wrong with it. Often, a narrative is most successful with a of flat and rounded characters. With that said, it's important to have strong character development overall to create rounded characters that have some depth to them. This helps characters being a real human being. Being able to relate to characters in this way, as a reader, makes them far more interesting and realistic.