What Happened to the Russians in Afghanistan?

When Putin invaded, he started to lose. Now it wasn't quite as obvious in some ways that there's an interesting new report out from the Royal United Servers Institute about preliminary lessons. But even so, perhaps maybe they would have taken Kiev. I can't help but feel that even if in that position they will be in precisely the same position as when Napoleon took Moscow. And frankly the Russians should have known it because this is exactly what happened in Afghanistan. They took Kabul and other main cities without relating that actually taking Afghanistan means taking the mountains and the hillsides rather than the handful of cities.