My daugther is will be 2 next month

i wanted to know when is the right age to teach her about not letting people touch you and not to go with strangers. Whenever i change her pamper i always tell her you dont let anyone touch you here or here or anywhere at all and she just looks @ me then i tell her when we are outside you dont take anything from anyone or go with any one or go on the street alone and she still just looks @ me. Is she to young to be taught all of that? should i continue doing it?