First two weeks of thermodynamics: gentle hand-holding through basic concepts. Week three: professor abandons you in the wilderness of partial derivatives. Week four: absolute zero isn't just a temperature—it's your exam score.
The emotional journey from "heat flows from hot to cold" to "derive the entropy change of this non-ideal gas using statistical mechanics" happens faster than an adiabatic process. And they wonder why students' enthusiasm approaches absolute zero by midterm.