I know a guy who likes to tell the following story about how he learned RPN: Back in college, his calculator battery died right before a big test. He borrowed

I know a guy who likes to tell the following story about how he learned RPN: Back in college, his calculator battery died right before a big test. He borrowed his roommate's calculator. It was an HP calculator. After failing that test, he made a point to both learn RPN and always keep extra batteries.