But that has presumably always been a pitfall for humans: trying to second guess the physical world and sometimes being "non-intuitively" wrong.
This is what humors me about analytical minded computation focused people vs dumb simple engineer and physics (practical) people. That is imagining all the infinities of what may change a physical result vs knowing by experience or education.
ANOVA: analysis of variance from linear fit parameters will show you in experimental data or simulation the contributing factors. Or you can read a chapter in an undergraduate heat transfer book.
Decay rate of (T(t) - T_inf)/(T(0) - T_inf) is probably dominated by the wind speed in your room. For an 8-12oz cup a sphere or cylinder will get you pretty close.