I know what you meant about being glad to learn something at our advance age, I just learned about the Oxford comma myself in the last few years - and was quite happy to recall its name! I had always used it before I found out some consider it optional, and now I often omit it - probably due to laziness.
Some examples where the Oxford comma SHOULD have been used...
“I’d like to thank my parents, Jesus and Oprah Winfrey.” (Besides suggesting that a child was born to Jesus and Oprah, the lack of a serial comma also implies that Jesus’s last name is Winfrey.)
“A notorious gambler, Charlie Sheen owed money to his ex-wives, Billy Bob Thornton and Hugh Grant.”
“This award is dedicated to my good friends, Young Jeezy and God.”
“…highlights of his global tour include encounters with Nelson Mandela, an 800-year-old demigod and a dildo collector.” (Note: this is a real example from The Times of London.)