What is arcane knowledge, for example, in the kabbalah

Benji's not sure about the kabbalah but the Fahrenheit system is definitely classifiable as arcane and secret mystical knowledge. All we know is 32 is freezing and 100-110 is extremely hot like up to or over 40 degrees Celsius. Everything else ranges from extremely mysterious and unknown to vaguely possible to know, example 60-80 or even 90 Fahrenheit means I might wear a sweater? I don't really know! Did you have to study at Hogwarts? Master of the Fahrenheit system, savant? To figure that out? God only knows....