I learned to deal with this by internalizing that any truly fantastic place is only temporary so I should enjoy it during the relatively short time it's fantastic. Once it gets beyond a certain level of popularity, it either degrades to a point where it's no longer exceptional, or it becomes too difficult to actually get into anymore.
In my town, there are a handful of truly exceptional restauranteurs who struggle with the very same issue. What they've taken to doing is starting exceptional restaurants and running them for a couple of years, then shutting them down and starting anew with different ones with different food styles in different locations.