Because the idiot (i.e. ME!) had pushed on his home computer and wanted to pull his work on his office computer. Don't ask me why they're different ATM...work in progress.
This doesn't make you an idiot. Being able to trust that this basic functionality (access controlled push/pull) will be available is why I pay for GitHub and decided to wait until GitLab stopped having avoidable, serious outages before considering them as an alternative.