I received a notice about not paying a ticket, 6+ years after I had paid for it. Lucky for me, I still had the paper receipt and so I went into the SF courthous

I received a notice about not paying a ticket, 6+ years after I had paid for it. Lucky for me, I still had the paper receipt and so I went into the SF courthouse to show proof of payment. After reviewing it, the clerk told me that it looked like their IT modernization had erroneously marked my case as being unpaid. I can't imagine how very painful the resolution process would have been if I had not kept that receipt.