Two kinds of momentum
There’s the unalterable momentum of physical objects as understood by physics: objects in motion tend to remain that way. A fast-moving baseball hitting your head hurts more than a lobbed one.
But usually, momentum is only conceptual, and it’s based on our habits and our difficulty in understanding (and ignoring) sunk costs. We stick with a pattern, a leader, an employee or a project much longer than we should.
The behavior that keeps someone from getting hired is trivial compared to what it takes to get fired. And at some level, that makes sense. When we’re not committed yet, the cost of looking around and switching our choice is small. But once we’ve emotionally committed to a cause or a project or a person, the cost of change is high, partly because it involves feeling as though we made a mistake.
But compounding that initial choice by doubling down on it is the actual mistake.
Digging a deeper hole rarely gets us to the other side.