The coordinating conjunctions among these are and and so.
However and therefore are not - they are subordinating.
Explanation:
It differs for each individual, what success is referred to. For some, the success is forming a family and being happy, while for others it's having the job of their dreams. Each individual does have control over their success, but not in every aspect. If they're after being successful, they have to work hard, not give up, stick to their standards and always remain focused on the goal. Although there are less aspects where the individual isn't in control of their succes, such as decease and general economic availability, they can also effect the rate of their success.
