How Important Is Memory?

If we didn't have any memory, would we be like worms? If we couldn't remember two seconds ago how would we detect fine changes over time and orient ourselves towards a meaningful goal? How would we be able to move forward with purpose if we didn't remember why we were moving to begin with? Would we just react to the most basic stimulus in the moment? Without a history of where we were coming from and where we intended to go, I can't imagine we wouldn't get stuck in the moment and only be concerned with immediate pain and pleasure.