A good idea might appear to be a good idea from an individuals perspective. To another person with a different perspective and knowledge they will arrive at a different conclusion.
The same is true for being right. You can feel that you are right. But you do not know what you do not know. Which can lead to two people having two very different perspectives. Leading to one thinking they are right and the other person knowing they are wrong.
Unfortunately there are so many factors which lead to miscommunication around right/wrong and good/ bad. Solving this difference though at times can take a lot of communication especially when two strong minds come up against one another.