It can be hell, at least certain parts. Ie., the 3-dimensional graphs of functions needed for analysis. Some grasp it easy, most don't. So this area requires a bit of practice. But it is neat, to see what holds in R, and what holds in R^n. So in essence, you can think multivariable calculus, as the generalization of concepts in single variable calculus. Make sure you review your calculus a bit.
If you are not taking a multivariable calculus course in the spring, I would suggest instead to learn Calculus 1 from a stronger perspective. You mentioned relearning calculus. Maybe take a gander at the book of Moise: Calculus. It is a bit easier than Spivak, Courant, Apostol, but does not skimp on the mathematics. Clear writing, and everything is explained. I gained a lot from his book. It is closer to Courant in style. To really appreciate multivariable calculus, some linear algebra is required. So maybe reviewing single variable Calculus and learning intro linear algebra would suit you well...