I am thinking of doing a theoretical physics PhD but i am worried about my knowledge on the subject. I am predicted at a first class degree. But i must honestly say i am not one of these prodigy types. I have to read over things a lot of the time and more often than not i will forget simple things which i have to look over again. Can anyone who has done a theoretical physics phd in any physics topic advise me on is this a good idea to do given what i have told you about myself? And what you do as a student in a phd? As i am worried i get accepted somewhere but be very diappointing because i dont know something i should or find it difficult.