Ive often heard from people that the lower-level maths (calc 1-2, intro to linear algebra etc etc) are difficult because they "weed" people out of the hard science programs... and the way things have been going with me I kind of am starting to hope its true. I am a BSC joint major in mathematics and economics. After some serious struggling with introductory calculus and linear algebra I got past those and finished all of the requirements for the economics part of my degree (econometrics, theory I-III in micro/macro, probability, statistics, financial econometrics, and a few social sciences.) So now I'm getting ready to take on the math side, which consists of multivariable calculus, elementary analysis, algebraic structure, applied linear algebra, discrete mathematics, ODE, and a few electives which will probably be financial mathematics and another abstract algebra. But to be honest I am stressing so hard as of right now just because I'm looking back at my calculus/linear algebra marks... I barely scraped by those courses. Cs and Ds to be honest, and I had to retake calc 2. I feel very worried about divulging into higher level math (even having taken probability/stats/econometrics). Has anyone else struggled at the lower level but ended up "blooming" when push came to shove? Maybe i'm surrounded by too many math prodigy kids but it really worried me when they talk about 4.0 gpas from the get go.