Your contribution to a job is not what you do, but rather the difference between your work and your replacement's work if you are not there. If your job allows you to choose, go for things that maximize that difference.

If you are a therapist, don't just go for the people who need the most. You might not be able to help any of them. Instead, choose those that you can impact the most compared to any other therapist.

If you are a computer scientist, don't go for the hardest problems. You might be terrible at solving them. Choose those what you can resolve in record time compared to any other programmer.

If you are a podcaster, don't just interview presidents. Pick those that you, and only you, can get them to open up and excel on the show.

Careers are not based on what any one of us can do, but what sets us apart from what everyone else could do.