As I type this, someone is having a “birthday.” And another. And another.
“Birthday” refers, or course, to another lap around the sun since the last observance stretching back to the time you left the womb and drew your first breath.
It’s actually an odd idea.
“Today is my birthday.”
Who is the “me” in this sentence?
- Skin cells fully regenerate in two to four weeks.
- Red blood cells are replaced every three to four months.
- Liver cells take about six months
- Bone cells hang around longer. It takes about ten years
- The heart and brain are still slower, and some may stick around for a long time.
So, the “me” that’s having a birthday isn’t physically the same person.
We take in over 10 million Mbs per second of data, so we know cognitively we are not the same person.
It’s fun to take note of such a milestone. But, in the words of Heraclitus . . .
“No man ever steps in the same river twice, for it’s not the same river and he’s not the same man.”