In San Fran we visited The Museum of Modern Art, and one photographer did a big impression on me :Nicholas Nixon
They showed his biggest work : The Brown Sisters.
Since 1975, he has taken a picture each year of his wife and her three sisters, every year in the same order.
I really liked, seeing the changes in their faces as the years has past. Aging, and how you live your life really shows, and he puts it right there.
If you get the time to read about, do it.
Nixon has created a powerful essay on the passage of time, capturing attendant changes and shifting moods while testifying to the enduring nature of family ties. When all 31 photographs made between 1975 and 2005 are examined, viewers can study not only incidental changes in background, lighting, and dress, but also the gradual, incremental aging of the women, and such momentous life-events as pregnancy. Close scrutiny also suggests changes in both the demeanor and psychology of the women and their relationships with each other.