In either 2006 or 2007 we did an 11 day WDW vacation, the first 9 at BoardWalk, the last 2 at POFQ. In the cab from BW to POFQ I said to wifey, 'You know, if we were going to the airport right now I'd be OK with that'. Don't misunderstand, I didn't want to leave, but I realized I'd had my fill. Ever since then, on trips mostly of 7 or 8 days, our last day was one of contentment, not depression. Even the stroll through MCO with all the new arrivees streaming past failed to dent our spirits.
I suppose it helps that we go pretty much every year, next week will be our second this year, and as we approach our senior years we do 10 days at the beach with the extended family and a week in March somewhere else. Having 15 WDW trips under the belt with no end in sight takes the edge off departure. Still, I remember the feeling, and good riddance to it. If it makes you feel any better, wifey used to work with a DVC member who visited WDW multiple times a year, and she'd go into a funk before even going there, in anticipation of having to leave at some point.
Bill From PA