For a 35 year old in general, never mind a world class fighter too, Izzy has a really fragile ego.
The Africa stuff clearly gets to him. Partly because hes kinda racist in general (then ironically he goes and defends Rogan comparing black people to monkeys) and partly because he knows himself deep down that he comes from a privileged background and abandoned his home country at a young age, and probably would never have had the career he had otherwise.