Hello. I'm actually taking Ph.D. course for plasma physics and I think I'll finish this course within this year. I took classes in quantum field theory and general relativity in last semester luckily and experience of these subject ignited a desire to study theoretical particle physics and cosmology. I've experienced physics research for many years and one thing I found from this experience is that I have persistence for finishing goals assigned to me but I'm not a type of person having a brilliant mind. Yes. I think I'm just one of average students; not bad but not superior. I feel such a self-evaluation, especially whenever I solve physics equations. I can handle them by using conventional technique or Matlab, but I hardly think clever short path toward the solution. I can make my understanding deeply for whatever subjects by studying hard for a long time and having self-questioning but I can't see an efficient way of studying so time can be saved. So, I would like to ask one question: how much brilliant mind is required for the theoretical particle physics and cosmology? Without this mind, even graduation is difficult?