If my memory is correct (and I can't be sure, since I was 5 years old at the time), I discovered TAS only shortly after discovering TOS. At least, I first saw TOS in January 1974 (I'm pretty sure), which was during TAS's network run. And I have a vague though unreliable memory of my mother coming out to me in the backyard not long thereafter and telling me that Star Trek
was on, even though it was Saturday morning rather than a weekday evening.
So for me as a child, ST was both a live-action and an animated show at the same time, and thus I never really made that great a distinction between them. They were both part of the same whole.