>>11773379Depends on what you mean by comprehend. You can get most of the basics with literally just finite dim. linear algebra and knowing what a probability is. You don't even need calculus if you only deal with time-independent Hamiltonians - Stone's theorem is just a restatement of the Schrodinger equation in that case.
Of course this won't be very satisfying if you're serious about learning what quantum really is. It really depends on why you want to learn the subject. For example, most PhDs in physics never actually learn QM the von Neumann way, i.e. functional analysis and operator algebras. There's simply no need for such formalism for most physicists. On the other hand, IMO anyone who works in this field should be comfortable with group theory, in particular the classic Lie groups and their algebras, and most importantly the representation theory of them.
