MeFi member hippybear explains how High Frame Rate (HFR) movies work in painstaking detail, and why some HFR movies look "weird" to us:
Because it looks TOO real. We're used to movies, even really great ones, having a veneer of "this is fake, this is a thing you are watching that was filmed". The colors, the lighting, the makeup, the flaws in the set... These are all things which, in 24fps, wash out a little, and our brain fills in the gaps, and we get a sense of reality because of what is missing.