Help needed to explain reflexive verbs

[aleCcowaN]

Me subí a la mesa [You are the source of power that lifted you there]
Salté por la borda (del velero) [You simply left gravity to do the trick]

but

Me caí por la borda [unlike the pretty impersonal account "caí por la borda", that "me" tells the event had severe personal consequences. Think of that like it is "me rompí el brazo" -I broke my arm-. In Spanish "rompí mi brazo" means you did it on purpose]