Lucky you! I also only play SP, but I'm always pulling a fast one on myself. Last night I sent an early Civ4 settler to a safe location—only one dark tile. But of course you know what was in that dark square… So I reloaded the auto save before I could stop myself.
I know it's going on tho, so I'm sure I'll catch myself one of these days. When I do, there'll be an accounting, I can assure you.