Observation by telling us about
(1) One experience you can personally recall that made you feel like you were nothing but a physical body - what you were doing that kept you completely focused on 'you' as a body moving in space and interacting with other bodies.
(2) One experience you can personally recall that made you feel like you were only a mental being - what you were doing that kept you completely focused on your inner mental life as a consciousness and made you feel like you had no body at all.
Be sure to tell us about both kinds of experiences you have personally had.