Having stayed away from home, and parents, for close to a decade now, I've quite gotten used to the state of affairs brought about by that particular fact. I visit my parents as often as I can get myself to, which is about once in three months or so. I like think of it as a quarterly report.. to assure them that I am in sound physical, mental and financial health. The average visit typically lasts two days... That number has been arrived at through complex mathematical calculations and has sound logic behind it, but it would be foolish of me to expect my audience to have my superlative grasp of math fundamentals. So for your benefit I'll present a simpler and more comprehensible explanation...
The day you land home you are treated like royalty. Your mom panders to your every whim and fancy, no matter how outlandish it is. For instance, imagine you said some like, "Mom, for lunch, I'd like to start with duck soup, followed by spaghetti and meatballs with Thai green curry on the side and finally a strawberry smoothie to wash it all down..". At any other time your mom would probably go ballistic and tell you in no uncertain terms what she thought of your suggestion and what you ought to do with it, but when you are only just back after a long stay away from home, you could expect not only to get away with it, but actually have your mom whip up your dream meal with a smile. Even dad is at his indulgent best around this time and allows you exclusive access rights to the TV remote, which is about as indulgent as any dad can ever get.
Day two is not too bad either. Mom continues to make choice dishes, though by this time the novelty of your presence has worn off and you can probably no longer expect unreasonable demands to be met with the equanimity of day one. The TV remote is still in your hands but by this time dad has begun making suggestions about what channel ought to be playing on TV... "They have this excellent show about international business on CNBC just about now. Hey, maybe we could catch that?"... leaving you feeling pretty much like a king whose powers are only ceremonial.
Day three onwards, your stock begins to plummet rather rapidly and pretty soon your standing in the house is lower than that of the neighbor's kid that your parents can't stand. Mom tells you to heat yesterday's dal and curry lying in the fridge and fix yourself a meal when you're hungry. And you can forget making outlandish culinary demands at this time... Such stupidity could have a serious impact on your short-term happiness, to say the least. Also, by this time any pretense about you being in charge of the TV remote has been done away with. The remote is back in dad's hands and you don't even have voting rights on what channel to watch. So much for your reign as the benevolent king of the remote....
Things go steadily south and it's not until the day of your departure approaches that your fortunes begin to change. And your rise to prominence is as dramatic as your earlier fall from grace. Come departure day and you are once again in a position to make unreasonable demands and have them met... and you are restored to your earlier position of power as the king of the entertainment apparatus in the house.
If you were to plot a graph of your standing in the house against the period of your stay, you'd come up with a very interesting looking graph... a variant of a graph that everyone who has ever been a student is familiar with... the inverted bell curve, with arrival day and departure day being the two high points and the dramatic waxing and waning of your fortunes in between. Now if you were to somehow eliminate all that stuff in between, you'd be left with only the two high points, making for the ideal trip home. Thus the correct answer is two... Hence proved!! Ta-dah!! Thank you... thank you all very much. I'm humbled by your amazement... Of course, there's also the small matter of the average weekend being exactly two days... until later... cheers... 8-)