Procrastination: I call this the slow killer of destiny, it has caused setback for many people, there are some life changing opportunities that occurs just once and many have failed to seize it, why? Cause of Procrastination. Well, one of the best ways to tackle it is to set target, implement your goals and work towards actualizing it.

 Wrong circle of friends: Your circle of friends could determine your level of success, there's this advice my dad always use to motivate us, he said a poor person in the circle of five rich people is a potential rich person, and that's cause the person would get informations or help from other friends to elevate him/her. One mustn't only consider rich friends but atleast your circle of friends should be with people who's got the mindset of acquiring wealth and are working towards achieving it.

 Fear of failure: The fear of failure has caused setback to many people, once someone kill there fears and go into a business, investment or project with the mind-set of success such person is bound to succeed so far they're working hard enough but once fear is entertained it could cause the person to easily give up on actualising their dreams.

 Fear of risk taking: Taking risk could be harmful if not calculated but not taking risk is even worst cause their are many opportunities involved in taking risks, a good percentage of successful people today are risk takers, so I believe the journey to success still requires taking risks.

 I believe there's lots more, but these are the ones I could think of however you could add more if you know any cause I believe these informations could serve as a motivations to some people who would come across this thread.