Thinking tool: Be a new homunculus
Guilt, sunk costs, or old commitments often drive people to work on things far longer than they should.
A useful trick, stolen entirely from Nate Soares, is to pretend you're a new homunculus - a lil guy in your head pulling the levers that control your body.
The new homunculus has no reason to honour the old one's sunk costs or commitments - it evaluates the situation on its current merits. It's also often very useful to shake off assumptions about what you can and can't do, and in organisations it is useful to challenge common beliefs/"ways of doing things" you've sleepwalked into.
Intel's exit from the memory business is a good example. In 1985, Intel's memory business, previously its main focus, was collapsing under Japanese competition. Andy Grove asked Gordon Moore (per Only the Paranoid Survive):
I asked, “If we got kicked out and the board brought in a new CEO, what do you think he would do?” Gordon answered without hesitation, “He would get us out of memories.” I stared at him, numb, then said, “Why shouldn’t you and I walk out the door, come back and do it ourselves?”
Related concepts
This is part of my thinking tools series.