Conflict in life comes from a variety of sources. So too, should conflict in writing. Some of the many types are represented by bullying, misunderstanding, and stubbornness. I’d include all the super evil bad guys, like Tolkien’s Sauron, under bullies. That one is pretty straight forward. It is the other two I want to cover right now.
Comedy often makes use of misunderstanding. One person says something and another person takes it, either out of context, or in a way the speaker did not intend. The result is the same, conflict born out of a lack of understanding. I have noticed some writers, particularly for sitcoms, take this to an extreme that becomes unrealistic, even for comedy. You can’t always rely on the same type of conflict for every situation. It’s great for one-line jokes or to create the main conflict, but to do it again and again get boring and isn’t what happens in reality.
While it is true that as writers, we aren’t creating reality with our words, we do have to create the illusion of reality - that these are people our readers can understand and relate to. Without that illusion, we won’t hold their attention. So all aspects of our story, weather grounded in reality or fantasy, need to have the illusion of reality. That include the series of problems we beset our characters with.
I’ve found stubbornness to be an equally normal source of conflict. For example, religious beliefs fall in this category. A religious person will hold to their beliefs regardless, in stubborn adherence to their faith. Similarly, a politician will hold to their political beliefs. Put two such people together with very opposite ideas that they will stubbornly hold to and you have an endless source of conflict.
The best written novels have one major source of conflict (like the Tolkien example from above) and a variety of other conflicts to bounce the characters around as they work to overcome the major conflict. Some novels use a series of smaller conflicts that build to the big climax. The not so good novels use a series of smaller conflicts that only serve as episodes to frustrate the characters and bring drama to the story, without forwarding to the main climax of the story. Soap Operas are famous for these strings of small conflicts.
Let's look at Gone With the Wind, at first glance, it might seem to be a Soap Opera. But it isn't. Although there are constant episodes that set Scarlett back, there is one overriding thing that lies behind every scene - a girl growing up. One by one, her childish ideas are removed, not always in time. Each conflict she faces whittles away her fantasies. The conflicts she faces are of all types. Her stubbornness causes many, misunderstanding abound, she faces danger from soldiers, starvation, troubles she causes herself, troubles she tried to avoid. While it is quite a list of conflicts she faces, it is an every changing landscape of conflict that rings true for her time and place. That is the key to good fiction, that your conflicts ring true for your setting.
And that is where the issue lies. They always say to write about what you know, but to be realistic, you have expand your horizons and be able to write from perspectives that aren’t yours. You can’t rely on stubborn characters just because you are. You have to expand. Not that you, the writer, have to change your beliefs, but you have to write characters that realistically differ from your beliefs. It is one of the skills to learn to take your writing to the next level. Many writers make a good living writing about the same types of characters and conflicts over and over, but the best writers can delve into a multitude of different characters and conflicts, a talent that adds rich realism to their writing.