In succeeding, there is no two ways about it, there is no pessimistic person who has been able to have success. Carry out a research and you would notice that practically all the successful men have one thing in common, which is a positive mindset. In any challenge, they know for sure that there would be a solution, whereas a poor mindset is a confused human who does not know his left from his right and at every opportunity, he complains and sees everything as being impossible.
On a personal note, the mindset is like an engine which needs to keep running in a positive light and if it eventually goes negative there is bound to be causalities. Let's take for instance, when a car's engine develops fault, no matter the fuel being put in the car, it would have difficulties in starting. The mindset is likened to the engine, in that, when once an individual has created for himself a negative mindset, it becomes very hard for him to change, no matter how another person tries to motivate him into thinking positively, which is likened to fueling the car which is the negative mindset being. This means that the mindset plays a vital role in our success.