>>8656436You'll want to start be relearning calculus the proper way with either Spivak or Apostol (I suggest Spivak). I think you'll realize quickly by skimming these books that your engineering calculus courses taught you almost nothing about calculus. So start there.
After that, the three basic foundational math courses are real analysis, abstract algebra, and general topology. Also linear algebra is important, so throw that in there somewhere, maybe before these three and after calculus.
Whatever you do, though, if you really want to learn math to understand it, stick to the textbooks that mathematics students use, not engineers (I'm not memeing here). And be patient. Mathematics takes a lot of effort to understand, and you will be frustrated and bored at first. So don't go into this thinking it'll be of the same nature as your calc courses.
