Nice explanation of monads! My two cents: personally, I would've started with the fact that a monad is exactly the stringing together of functions (a -> m b),

Nice explanation of monads! My two cents: personally, I would've started with the fact that a monad is exactly the stringing together of functions (a -> m b), and the similarity between monoids, monads, strings / lists and functions under composition. You mentioned that • (a -> [b]) is the type of non-deterministic computations • (a -> Maybe b) is the type of fallible computations • (a -> IO b) is the type of effectful computations • (a -> (s, b)) is the type of computations with state s • that the Monad instance merely specifies how to compose them • all such composable constructs can be expressed as a monad • do notation and list comprehensions automatically work across all of them and, in my opinion, these are all much more powerful motivation than beginning with a comparison to functors.