I know they are not, but when I hear people assert they cannot tell the difference between 4K, 5K and low-res 1080p and below (etc.) I just think they have to be lying.

The difference is so obvious and plain to me that…how could you not be able to tell? It’s like having a kitten and a T. Rex in front of you and saying, “These look the same to me. No difference at all.”

Human visual systems just aren’t that different. I don’t have Superman eyes. What’s going on here? (And yes I can tell reliably even when I don’t know what the monitor is.)