A few years ago I quit my job to be a stay-at-home dad with my young kids for about 8 months. There was an issue with the kid's daycare and I left my company kind of abruptly. During that 8 months, even though I no longer worked there, I used to get calls about how to find something or use something within our company's ERP software. Not many...maybe one a week. And it was always something extremely simple to fix, like how to print a certain report, or how to check the status of a purchase order. Pretty basic things that all employees should know but seemed to have ongoing issues with. I spent maybe 5-10 minutes a week helping with these phone calls.