Some people like to do only what they already do well. Other people prefer to try new things and take risks.
Of the two options - doing things again which I have already done well and trying new things, I will like to choose to try new things and take risk. There are several reasons behind my choice which are explained below.
First of all, doing some old thing which I have already done in a remarkable way is surely a boring task to do. To do that task in a superior way, I must have done that several number of times. Without performing that task more than once, I would not have got mastery in that task. Therefore, if somebody tells me to do that task as I can do that well, I will simply refuse to do so. Because I will not get any new experience by doing that same task. I cannot taste something new by again executing same problem. Instead, if I do something new challenging work, I would rather gain a new experience. For an example, in my office, I have already mastered one algorithm. I have solved many problems by dint of that algorithm. So my boss tends to give me only those tasks which can be solved with that algorithm. Here, I am not able to experience or learn some other method of solving problems. Therefore, I wish to take another problem which can be solved with some other method.
Secondly, by doing some new things and take risks, I can gather much knowledge. If I continue to do some old thing, my knowledge gathering will be stalled. To me, if someone does not increase his/her knowledge, then he/she is stagnant. That kind of people will be of little use to the society. By involving with something new, by taking risk, we can acquire precious knowledge. This knowledge will help us to lead a better life. We can also pass that knowledge to our posterity. For an example, while driving I try to explore some new route. Most of the days I end up circling around same point. But, sometimes I found one quick route to go to some place. If I would have taken same route every day, I could not have known that such route exists. So, my knowledge about the routes increased by taking a simple risk. Like this we should take risk and try new things in other fields of our daily life too.
Finally, to perform any task, some amount of skill is required. That skill will be developed, when we do that task again and again. At some point the skill will be at apex. Then, there will be nothing to develop to perform that task. So, to develop another skill, we have to try new thing. In today's society, to survive smoothly, multiple skills are needed. Because, may be, some day or other the only skill someone developed will be obsolete. That day, the person will have nothing to do to earn his/her livelihood. If he would have tried new things beforehand, he would have grown some other skills which might be useful in stressful days. For an example, in the time of recession, all bankers and software engineer lost their job in USA. But, people who had mechanical engineering or construction engineering knowledge, continued to survive. So, if a software guy would have learnt little mechanical or civil knowledge then he would have little sorrow on those days.
Therefore, to make a gist, it is advisable to try new things and take risks because by doing so, we can make ourselves and our society better in many ways.