Many of the decisions I’ve made in the past have been driven by the sunk-cost fallacy; choosing to continually invest in something because I’ve invested so much in it already instead of whether or not the benefits of further investment will be worth it.
But, this is where it’s useful to remember the old Japanese proverb: When you’re on the wrong train, get off at the next stop. The longer you wait, the more expensive the return trip is.
The tricky part is working out if you’re really on the wrong train and, to know that, you need to know which train you’re supposed to be on and, to know that, one needs to know one’s self.