You've touched on one of the most important elements of human nature, which is our inability to ignore sunk costs. Sunk costs are the unspoken minefield of mistake in which we rationalize why we have to justify the thing we already have, we invent new meanings for the word 'momentum' well beyond Isaac Newton, and we imagine that we have to stick with what we did. So, much of the time, learning to ignore sunk costs is the single most useful thing I can point out to people.