Every 7 years the majority our cells completely regenerate. As such, you are essentially an entirely “new you”. This is a constant cycle, cells dying and being born, happening moment to moment at a rate of 168,515 cells/sec. (An estimate based on our best guess at the number of cells in the body using 7 years as average cell cycle time frame across cell types.)
This mannequin projection attempts to bring awareness to this ever-occuring process, allowing us to consider both our mortality and "immortality" during the continual and complete cellular renewal happening several times over in the average life span. It also allows one to consider the opportunity to "completely change" the self, that making changes now has a lasting effect.