Many people start off businesses without conducting any market research and its rampant amongst young people. This could also be classified as overconfidence, but it’s such a large issue that it needs its own segment.
People are lazy when they don’t prioritize what they are doing. They procrastinate, do other things they are more interested in, and only come back to the task when it becomes urgent, or they finally see a need to get it done. My friend only saw law studies as his priority early on, but after realizing the need for stellar grades, began placing his other subjects as top priority. Everything he did was geared towards fulfilling his dream.