Papyrus gave Sans more credit for everything than he had ever deserved. Maybe he was a good enough brother back before... pretty much everything. He doesn't even really remember anymore, between the wearing of years and the pointed amnesia that's come in between. Sans has a lot of memory gaps about that time as well, but at least he's always known what was missing. Who was missing.

The words stick in his throat for a few painful moments before he can finally spit them out, with a feeling like something snapping.

"Everyone forgot him... like I forgot you, here. Everyone except me. I was the only one who knew what happened but nobody else even knew the difference. He was just... gone, and I couldn't get him back."

"I tried," he explains a moment later, a heavy weight of resignation in his voice. He'd tried and he'd failed. "Doesn't sound like something I'd do, right? But I really did."