I don't believe that was the intent of your parent. The 6 hours of tattooing was instead a scenario they have personally experienced where they have also observed others having wildly divergent experiences from themselves, despite the same inputs, and are using that to bootstrap a framework for understanding how wildly different others' experiences with hunger might be from their own.

It definitely belies a level of privilege that some people must intentionally seek out discomfort or pain in order to begin to even approximate the agony others are inherently forced to live through. I don't believe privilege is itself a moral failing, or we're stuck with whole categories of 'original sin'. It's what objectives its used to enable that potentially indict those that possess it.

The comparison was that for some it may be excruciating and that others it may not. Maybe a tattoo isn't the best analogy, but their main point is apropos to the idea that understanding the experience of others may be difficult when there is a wider range of experience than many want to admit.