no seriously
if you draw solely from imagination you'll have pretty forgeted up proportions and death
no???
this is what learning anatomy is for, so you don't have to keep using references and can draw poses from a formula
referencing is important too but being able to replicate what's in your head using the skills you learned is the highest level.
alternatively people just learn anatomy from trial and error which actually works quite well for them
EDIT: y'know what drawing is subjective and different people learn different ways so try to assess what you want out of a method before trying either
