Don't think of the walrus as being an assignment. You can conceptualize it that way, but you shouldn't; that thought will be unhelpful in producing and reading code. Assignment is still the normal =, with a variable on the left and the value you want to put in it on the right.

The walrus is for giving names to values you were computing anyway. Instead of a storage bin and the value you want to store there, the walrus involves a value and the name you want to refer to it by. Conceptually, the value is where you begin.