I am a PhD student in pure math, now in my second year. I understand that different PhD supervisors have different levels of involvement with their students' projects, and I very much appreciate how engaged my supervisor is with what I am working on. However, there is something that concerns me regarding whether the input my supervisor has is appropriate.
He is mind-bogglingly quick and can sometimes outline proofs of new results during our meetings, which I then spend days making sense of, writing up properly in full detail, refining arguments where necessary etc. Sometimes he sends me notes via email containing unpublished results, with very little context. I do not ask him to do any of this, however I am very grateful for his help. Is this type of input unusual?
My main concern is that when writing up my thesis I may have to add in lots of disclaimers such as 'this proof has been communicated to me offline by...' to acknowledge that the original idea is not my own. Would this look really bad? Also, some of what he has sent me are results that I likely would have been able to do by myself given a bit more time, but I cannot demonstrate that now because he has beaten me to it.
Communicating my concerns to him is tricky because in my experience he does not respond well to questions unless they are of a strictly mathematical nature and I do not want to appear ungrateful for his efforts. Any suggestions or advice would be much appreciated.