I realise a maths PhD is completely different from other science PhD, like we don't have any lab work. I still have this confidence issue. I can't stop thinking, can I really solve some unsolved problems? What if I can't prove anything new in 3 years' time? My supervisor seems very supportive, but sometimes I am scared to ask him to explain something, in case it might sound stupid. Don't know what to do really. It would be great to hear how other people are doing.