The Stoics offer not a set of beliefs but a set of practices — a way of seeing that you can try on, right now, and keep if it helps.
Farnsworth's opening move demolishes the biggest misconception about Stoicism: that it's a rigid doctrine. It's not. It's a toolkit. You don't have to believe in Stoic metaphysics to benefit from Stoic psychology. Try the practices, keep what works.