My number one favorite time is after I sold a company. Two years later, the company contacted me as the old CTO and asked me about some piece of core technology

My number one favorite time is after I sold a company. Two years later, the company contacted me as the old CTO and asked me about some piece of core technology. They asked me to take them through it and show them what was going on since they wanted to migrate it into something else. My first question was, "Haven't the other developers ever touched it." They said no. This core piece of technology scaled to way more users and was essential to making 100s of thousands of dollars for the company. It didn't even break once in two years. It was core to the service and they were just asking how to move it. I was so proud of previous me.