The sprint within the marathon.
You rarely see a professional marathon runner doing a sprint while running a marathon. It simply doesn't work. They know that if they sprint, they are highly unlikely to complete the marathon, leave alone win it.
But when it comes to our work, we feel tempted to do exactly that, to push harder this day, this week, this quarter. We see it as an exception, as a one-off. We convince ourselves that things will be back to normal soon.
But things are rarely back to normal. So, we burn out, we crash, and we adversely affect our physical and mental health and our relationships.
A marathon is not a series of sprints and your generous work is almost always a marathon, not a sprint.