People get used to anything, become disenchanted with everything... Is Mount Fuji less beautiful now than the first time one saw it? Is the warmth from the sun different before/after sun-burn?
Regardless of the time scales involved in the impermanence of the physical and biological laws we know (sure, Mount Fuji will erode eventually, but that day is quite distant), our interpretation of phenomena changes at a very fast pace.
Which impermanence should one focus on, to improve one's life? There's a danger of disenchanting the understanding of impermanence... Seon's "What is this?" is a relevant question at any time, no matter how often repeated!