I don’t know if I’ve got this completely wrong, because I self taught myself mathematics. I did algebra before I did calculus, after which I did Complex Analysis. In algebra I did everything first (basic to college and high school to linear algebra and set theory and group theory, etc.) and then I did Calculus (derivatives to integrals to Taylor series to line integration etc.) and then in Complex Analysis I did stuff like contour integration, Laurent series, roots of unity, transforms, etc. Is there a better (more conventional) order to have learnt these? What kind of mathematics is harder than Complex Analysis? Is it weird I find ‘modern algebra’ and ‘real analysis’ extremely easy and I find complex analysis as a challenge?