If I am not mistaken , Europeans also believed Egyptian mummy had some kind of healing powercure . I can ' t imagine all the history lost because of such stupidity . g r u e s o m e h i s t o r y ofeatingcorpsesasmedicine 82360284 <| sep |> You can learn some simple assertive scripts and deploy them as needed . Friend , I ' m going to see prof x . You want to come with ? You sure ? OK then , see you later . Sorry , dad , I have this testassignmentwhatever that ' s stressing me out and I really want to get it out of the way first , but I ' d be glaad to help later . How about tomorrow afternoon , that good ? I ' d have offered tomorrow , but then I ' m meeting X at y o ' clock . Let ' s make plans for next weekend , and in the future please tell me when you ' ll need me enough in advance so I can be sure to be free at that timerephraseadapt to your family culture as needed . it ' s not a 01 game you ' re allowed to say , I can ' t now but maybe later and dude , can ' t explain X thing to you now , I ' m studying for Y subject next time come with me when I ask you to come visit prof Z