Think of an experience from your childhood. Something you remember clearly, something you can see, feel, maybe even smell, as if you were really there. After all, you really were there at the time, weren’t you? How else would you remember it?

But here is the bombshell: you weren’t there.

Not a single atom that is in your body today was there when that event took place … Matter flows from place to place and momentarily comes together to be you.

Whatever you are, therefore, you are not the stuff of which you are made.

If that doesn’t make the hair stand up on the back of your neck, read it again until it does, because it is important.

All your cells and atoms have been replaced since then -- this is not true, but it is partially true and food for thought.

Different types of cells have different lifespans, e.g.: 

• we shed our skin cells about every 35 days

• red blood cells live about 120 days, platelets 6 days and white cells less than a day

• most of the adult skeleton is replaced about every 10 years

• the average age of a fat cell seems to be about 10 years

• a 25-year-old heart replaces about 1% of all its cardiomyocytes (heart muscle cells ) over the course of a year, while a 75-year-old heart replaces about half a percent

• our neocortical neurons, the cell type that mediates much of our cognition, are produced prenatally and retained for our entire lifespan

Neural cells are not replaced at all.