Factory reset didnt work...
I sold my MacBook Air. Before I did that I factory reset my Mac. I followed every instruction provided from the apple article on what to do before selling your Mac. I met with the man I was selling it to, and everything looked fine. When the Mac was opened the screen showed the startup menu you get when you buy a new Mac. BUT later that evening he sent me a picture of the mac-screen, asking what my password were. And it seems after all the factory resetting my useraccount is STILL THERE, even though I watched him make his own. Apple-ID and iCloud are not I think. But still I'm kinda annoyed. What happened here? I erased everything with disk utilities and re-installed macOS and everything