Reading book of the same name by <some guy> in preparation for interviews. Probably will skim through Art of Electronics and Practical Electronics for Inventors too.
TODO: “an analysis can tell you that a certain cutoff frequency is proportional to the square root of the ratio of two capacitor values.” ???
Make a more stable filter/everything design by adding two of something that vary with temperature together. You wouldn't have known that from simulation unless it took tempreature into account.