Picture one flat plate on the ground. You leave from it, you go all the way around, and nothing you did counts until you come back and touch it again. The plate itself is nothing special — what matters is that it is both the starting point and the point you have to return to.
可以想成地上那一塊板子：你從這裡出發，繞一整圈，回到這裡踩一下，這一趟才算數。板子本身沒什麼特別，重點在它同時是「出發點」和「一定要回來的點」。這個畫面是幫忙記憶用的聯想，不是在說這個詞的來源。
登入就可以看每一支怎麼連回核心畫面。