@mediumcool "off that watch" and "off of that watch" are both acceptable grammatically, but i think "off that watch" sounds a little more informal and casual
(but anyway "off of" is the regularized form of that structure; "off" in isolation is eliding the root preposition of the prepositional phrase, which is totally fine because language does all kinds of idiomatic things but *it* is the variant that is, formally speaking, irregular, so you could reasonably expect "off of" to arise organically in speakers as an inferred rule even without it being explicitly taught)
nothing at all
nothing at all