Outside of some cells in the brain all the cells do get replaced. But there are some that have lifespans of over a year (white blood cells) and some only a few days (cells in a human colon)

Osteocytes in your bone have a half life of 25 years, and many of them don't get "replaced" even after they die.

It's not just the reality of life, it's the essense of reality. Everything "real" is looks like the Ship of Theseus and if something doesn't look like that ship, it's not real.

Do you have a source for your claim?

Not sure it's on the GP to provide a source but here's one:

https://www.timeshighereducation.com/news/life-span-of-human...

I like how HN downvotes when asking for a “source”.

I was merely expecting a “this is false because of X”. Rather than “this is false”

I guess we all have our biases.

Does the person he's replying to?