> avoiding sunk-cost thinking The past is in the past. The half a billion matters insofar as it's given us our current playing hand. The right mentality is som

> avoiding sunk-cost thinking The past is in the past. The half a billion matters insofar as it's given us our current playing hand. The right mentality is some combination of looking forward (we have many options, some of which were bought for half a billion, but even those might be worthless), backward looking (half a billion is probably worth having a retro over; was the outcome regrettable? If so, how can we do less of that?), and keeping non-obvious systemic effects in mind while doing both of those things (e.g., if you never finish a project, it doesn't matter if you were always working toward the "right" thing, and with that sort of thing in mind your bias toward cancelling projects should perhaps be weaker than the immediate facts might indicate). Imagine you'd invested half a billion in Theranos. You really would have pennies on the dollar in return, and completely scrapping it (or otherwise selling it for parts) could be a logical move. The sunk cost fallacy comes in when you decide that because you've already invested you need to continue in that direction. Your point about it being hard to wrap your head around scrapping it entirely is a little subtle. We very well might have bought something worthwhile for that half a billion. In that case though, you still want to look at the resources you _currently_ have available or expect to have in the future, not the fact that you lost a half billion (except insofar as you can use that as a learning experience to not fuck up so much in the future).