Real World intuition is a habit one needs to abstain from to be able to be creative in the field of higher level mathematics.
I have a bad feeling that also modern physics who has been pretty much stale since the early twentieth century is not due to lack of intuition but due to lack of mathematical models.
As for Heaviside he was self taught, an engineer in spirit rather than a mathematician. In a more modern mathematical perspective, not derived by intuition, Maxwell equations are just one very simple equation in Clifford algebric spaces. This formulation will not prevail since the engineering (intutitive + sleigh of hands) approach has dominated instant gratification higher educational level curricula.
I am not saying that what I am doing is different, I am from an engineer background also.
But having had that mindset, I eventually met mathematical minds and was humbled by their vastly different approach. This approach is not for everybody though, the yellow books are difficult to parse. Having said that I find that the mathematical mathematics approach is applicable in all of engineering whereas the engineering mathematics approach is not applicable in all of math.