Habitual residence (Nature person)

I am alway amased when I see the law-makers presume that the ordinary citisens understanding the meaning of "habitual residence". Many legal documents take use of this phrase to determine the important legal status of persons. This terminology, however, is too much a legal jargon for normal citisens to understand. Even legal practitioners, or scholars, are confused for its precise meaning. Habitual residence is far more difficult than the simple idea of "where are you living". Especially in the contemporary world, where people are continuely moving and travelling. If somebody asks me "where are you living", I might say "England". But if someone asks "where is your habitual residence", I might feel confused. My current status is that I am living in England for 3 years, and my permenant residence is in China. I might wonder where can be regarded as "habitual residence" for me. 3 years might be long enough to make England my habitual residence. But, how about 2 year? 1 year? Half a year? Or 3 months? How long the period of time is sufficient to make a state one person's habitual residence? Also, the lenght of stay cannot be regarded as conclusive. For example, if somebody has been in China for 20 years, and he has just left for England last month. This period of time might be too short accroding to English law to make England as his habitual residence. But, if this person has made up his mind to stay in England forever, can the court still regard China as his habitual residence? It seems this person, once made up his mind and took the action, will adjust his behavior according to the law and customs in England instead of in China. He will except to be governed by the law of England and be taken to the English court. It is more logical and reasonable to decide habitual residence simply based on the time of stay.