Most entrepreneurs fail for several common reasons: (1) Trying to do everything alone instead of sharing work, (2) Running a business only part-time instead of full-time, and (3) Lacking a clear business plan and revenue model. Other reasons include unrealistic expectations of help from others, poor networking skills, ego that prevents listening to advice, and not recognizing the importance of employees. To succeed, entrepreneurs must avoid these pitfalls and focus on building a sustainable business model.