The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.
The best architecture comes from a synthesis of all the elements that separately comprise a building: the structure that holds it up; the services that allow it to function; the ecology of the building - its relationship to the surroundings; the quality of natural light; the symbolism of the form; the relationship of the building to the skyline.