You're confusing the way things are now with the way things must be, for some reason. Just because things are one way right now doesn't mean they won't be another way in the future. Especially if new technology comes along that disrupts the field.
This is true, I was responding to the parent post in particular. Right now, you can't be certain and that's part of the allure.
Many (most?) people, for instance, get tattoos to commemorate important events or people. The entire point of a tattoo in those cases is that it's permanent.
The more fundamental point of a tattoo is that it's decorative. There is an entire genre of tattoo ( https://en.wikipedia.org/wiki/Lower-back_tattoo ) which is definitely not supposed to commemorate anything other than the sentiment "hey, look at me!"
