Low iq, low work ethic, mental health issues (that negatively effect your work).
Nah. My brother never graduated from high school (low traditional IQ), was kicked out of our home due to delinquency, and had to hide in Alaska for awhile due to having a warrant out for his arrest. He worked his way up to being one of the top oil base managers in the world, making more money than pretty much anyone else I know. He also was bipolar, completely dysfunctional in family relations, and a raging alcoholic when not working (i.e., he would drink all night and work long days, and go on binges when he was off work for a time).
Work ethic is important, but you also need to find the thing that you are passionate about and/or really good at to help you enter that work ethic properly. Also, a huge part of career success is being in the right place at the right time and knowing the right people. General education is critical for a healthy informed society, but more importantly individuals need the specific education and mentorship that reveals their talents.
