There are two ways sunken costs can trick us.
The first is believing that because we’ve already bought something — invested time or money into it — that we must use it to get our money’s worth.
That’s not to say we should be wasteful, but it does mean that we have to drink the rest of the bottle.
The second way they get us is when we think that we’ve put in enough.
We think that we’ve invested enough to be sure that another minute won’t achieve anything.
Often, that’s the moment when a little extra push would bring success.
Sunken costs hurt us both ways. There’s no way to tell the difference.
The best we can do for ourselves is ignore them altogether.
Because as much as we like to draw lines between the past and present, the only connection they have to the future is the one we choose to make right now.