Reminds me how once I had a math test in college about simplifying trigonometric expressions (cos(a + b) kind of formulas) and I made a cheat sheet with all the

Reminds me how once I had a math test in college about simplifying trigonometric expressions (cos(a + b) kind of formulas) and I made a cheat sheet with all the formulas because I couldn’t remember them all. Obviously I forgot one formula and as fate would have it it was on my test. Took me about 15 min, but eventually I derived it and put it all on the test paper. My gosh the math professor was proud of me, probably one of the top 10 moments of my life when he kept boasting about it when he announced the test results. Many years later I kept thinking I should tell him the full story, but alas he died not too long ago. RIP ‘Stakan Stakanovich’