How to be fearless as Ph.D student? I am a computer science Ph.D. student. I have written a couple of research papers and some of them are under review. I have started becoming fearless from some time as my past experience has told me that with time and with hard work every research problem is solvable to some extent (make something publishable out of it). I have tried to now pick the research which is less related to my previous research works. I am doing this thing on purposefully as I don't want to narrow my research domain. My belief so far is that pick something read few papers for some months and purpose a question take more months and then write it. 

Question: I am wondering what are the other things which I can try to be more fearless or what are the things students should practice in order to become more and more fearless? I used to a person with lots of fear but now I have become confident. I know fear some time push me but after failing some projects I have become a fearless person. 

Some meaning of the fear is to take the courage to pick a research problem and solve it and make it publishable.
I'd say that you must learn not to take things too close to your heart. "Fear" appears when something hurts our self-esteem. The key is to realize that in most cases it should not. Say, a reviewer rejects your paper, providing very harsh comments. You feel like jumping between a cold shower and a frying pan, but you should't. Reviewers don't know you personally, they are only doing a job of bashing your paper if it's not good enough. If you paper is not good enough, it doesn't mean that you aren't good enough, so your self-esteem shouldn't suffer. (And it especially shouldn't suffer if a reviewer is wrong.) Accept criticism and continue. 

If you fail, often it means that you aim high, so it is normal to fail. We aren't in school where all problems have ready answers. Many directions are dead ends, and we must realize that it's OK to hit a dead end from time to time.

In a sense, it is equally important to practice humility. A huge number of talented people establish start-ups, record songs, write novels and draw comic strips. Most of them fail, this is just the way it is, and we shouldn't think of ourselves as exceptions. Accept that failures are as inevitable as gravity (so, once again, don't take it too close to heart). It is also useful to understand your limits. We all have stronger sides and weaker sides, and even our stronger sides in most cases won't get us a Nobel prize next year. Aim high, but stay realistic with your goals.

In short, be passionate about your topic, but try to keep your inner self "protected". It should not suffer when you are hurt as a professional (due to failures or criticism). It is hard, but doable to some extent.