One can easily distinguish a serious entrepreneur from someone who is temporarily passing through a stage of entrepreneurial activity based on how deeply ingrained entrepreneurship is in his/her psyche.
Some characteristics that indicate that one is suited for entrepreneurship long term, include
a) Ability to take charge of a business from start to finish (not just in parts) - One need not be an expert in all departments (e.g., HR, Marketing, Finance etc), but needs to possess a working knowledge of all departments and see the big picture of how they are inter-related and lead to the success of an enterprise. One should be able to have a balanced view of all departments and not a skewed one. Some people give excess credit to business development related contributions as compared to execution and HR and vice versa. A balanced view is required.
b) Ability to generate revenues and profits on your own - This is a strong indicator of entrepreneurial capability. If you are capable of heading and taking charge of a profit making center and scaling it up without being dependent on other business units to sustain, you are a strong candidate for entrepreneurship
c) High level of ambition and aspiration - If you are not content with a steady income. Do you need constant growth to such an extent that you reach increasing levels of discontent with stagnation?
d) High level of disdain for being an employee - If you cannot imagine yourself in a job either now or ever. If you feel like showing contempt for any competitor who offers you a job (no matter how lucrative).
e) Good people skills and ability to work well in a team - If you get along with clients, partners, employees, consultants etc well and are able to complement others in a team environment to achieve a common goal, you can be a successful entrepreneur.
f) Commitment to a goal and passion to achieve it - If you have a vision and a goal and you are passionate to achieve it. The goal may be part monetary and part game changing. Pure monetary goals or pure non-monetary alone may not be sufficient. A balance is required between making money and impact on the industry and society. If you are committed to make an impact on the industry, generate employment etc and you are passionate to do what it takes to make that impact.
g) Responsibility and proactive attitude - If you avoid blaming external circumstances, employees, clients, partners, investors etc and take responsibility for the outcomes of your actions. You believe that you can make a difference and do what it takes. If you make a mistake, you admit it, learn from it, and move on.
If you look at only one piece of the puzzle at a time and blame the inputs, resources etc that you were given for your lack of success, perhaps a job with limited responsibility would be good for you. If you have a 'chalta hai' (It's alright. That's the way things are) or 'main kya karoon' (what can i do? i am helpless) attitude, entrepreneurship is not for you.