If they say that all human cells replace themselves every 7 years or so, why can scars remain on your body for the entire life?

Question

If they say that all human cells replace themselves every 7 years or so, why can scars remain on your body for the entire life?

In:

Answer 1

Imagine the body like a building.

The connective tissue (collagen mostly) = [steel skeleton](https://www.dreamstime.com/steel-skeleton-tall-building-under-construction-crane-tower-steel-skeleton-tall-building-under-construction-crane-image123978264)
The human cells = the bricks, windows, doors, everything in between.

A scar is usually a damage to this steel skeleton not the bricks/walls because they can always be changed.