A retired teacher from Lodi, California, received an unexpected reminder of his teaching days — a geometry book borrowed by a student four decades ago.Rod Woznick, a former teacher, said he was surprised when he opened a package in the mail and saw the sender’s name, Brent Gentner, a name he faintly remembered. Inside the package was one of his old geometry textbooks — and a handwritten note.“The note said, ‘Rod, I found this book which belongs to you. Thank you for letting me borrow it for the last 40 years. Sincerely, Brent Gentner,’” Woznick recalled. “I was more shocked when I read the note, saying ‘I’ve had it for 40 years.’”Gentner, who now works as a software and electrical engineer in Florida, said he came across the book while unpacking old boxes. “I was kind of a nerd back then,” he said. “I was interested in math and science, and he had books students could check out. I just thought it’d be kind of funny — 40 years later.”Even after all this time, Gentner still…..