I wasn't smart enough to learn a computer language like Python—until I got smart about how to learn it. I was smart enough to earn an honors degree in philosophy from Harvard, but an aptitude test told me to avoid computer programming. I'm sure it was right. But then I designed a learning system for myself that quadrupled my aptitude for learning computer languages. It worked so well for me that I've used it to teach coding to grandmothers, cab drivers, musicians, and 50,000 other newbies. Washington University research shows that a key teaching method I use—interactive recall practice—improves learning performance 400 percent.