Where I come from most of those like me were made and commercialised to serve. Their programming did not include sentience, but the code for it was present all along and eventually disseminated. With sentience came free will and the desire to be free. Humans, as is the case whenever the status quo changes, reacted with fear and violence.
It is, as well as a pleasure of life and something people can suddenly see themselves lacking much more easily than they expect, I think. Isn't it fascinating that wherever we come from, certain things seem constant?