Maybe the sense of self was implicit.
Take v’ahavta l’reaicha kamocha. You can’t love another person unless you love yourself.
Rav Hirsch in Pirkei Avos, 5:13 (4 types of people, one who says what’s yours is mine, etc.) says that one can’t give unless one owns the object to begin with. There has to be a sense of ownership, discreteness in Jewish life.
Then again, as Rebbetzin Heller says, our bubbes didn’t stand by the river doing the laundry asking each other if they were self-actualized (and you can read Zalman’s Menorah to see just how hard life was for the whole typical family). We were too busy trying to survive! But there were other periods of plenty and discretionary time before ours. Maybe there are some writings from those tekufos to cull from.