I had no idea benzene was used to decaffeinate coffee [1]. Solvent separation makes sense, but I'd never really thought about it. Definitely not a residue I'd want to drink.
From an amateur chemistry perspective, benzene is so fascinating. Benzene rings are one of the first, maybe the very first, structures students learn that don't have fixed, discrete bond counts. That they can be interpreted as a cloud of 1.5-electron bonds between each of the 6 carbons, or alternating double- and single-bonds, makes for some interesting hand analysis of molecules.
[1] https://en.wikipedia.org/wiki/Decaffeination#Direct_method
Also that Benzene led to the creation of the field of organic chemistry.
