Yeah I think you and your art teacher are spot on.
To me... animation (2d or 3d or 4d) is broken into 3 things
Physics - which can be learned and mastered.
Drawing/Design - which you can improve on... but you will probably feel as though your stuff is never quite good enough... which is good cause it will make you improve more.
Acting - Same as Drawing/Design... with learning and observing you can definitely get good at this, but you will probably always want to be better... from Disney to south park... it all requires clarity.
The good thing about mastering
physics is it will make the other 2 easier to deal with. It will (sadly) take the 'magic' out of animation and it will make your decisions much easier to make.
Back in me pencil paper days, physics helped my drawing. If I was struggling with a drawing, I would check my arcs and spacing and it would tell me where everything would have to be on the next frame... woh la! much better looking drawing.
sheesh... blah blah blah
