Title registration rant

We sold a car once, signed over the title to the purchaser. Two years later, we were approached by a gentleman we had never met that was now the 3rd or 4th purchaser since we had signed over the title. No one had ever transferred it to their own name. We, the original owners had to file for a duplicate title ( we needed the VIN # to do that, luckily we still had some paperwork) and then after we received the duplicate title, we had to sign it over to the current owner. That time we met at the DMV and made sure it was put into his name and not left in our name.