genius is not what you think
Relying on intelligence alone to pull things off at the last minute may work for a while, but generally speaking at a higher level it doesn’t.
One needs to do a serious amount of reading and writing, and not just thinking, in order to get anywhere serious in STEM; contrary to public opinion, breakthroughs are not powered solely (or even primarily) by “Eureka” moments of genius, but are in fact largely a product of hard work, directed of course by experience and intuition.
The devil is often in the details; if you think you understand a piece of mathematics, you should be able to back that up by having read all the relevant literature and having written down at least a sketch of how that piece of mathematics goes, and then ultimately writing up a complete and detailed treatment of the topic.
It would be very nice if one could just dream up the grand ideas and let some "lesser mortals" fill in the details, but it doesn't work like that at all; past experience has shown that it is only worth paying one's time and attention to areas in which a substantial amount of detail and other supporting evidence (or at least a "proof-of-concept") has already been carefully gathered to support one's "grand idea". If the originator of the idea is unwilling to do this, chances are that no-one else will do so either.