nag at

Still, in the weeks and months following the decoder experiments, the unsettling implications of the device began to nag at him.

For all that he did this season, the Mariners’ failure to reach to the postseason and his own inconsistencies will nag at him all offseason and motivate him through workouts.

What did nag at Winslow, he said, was the question of whether crime writers put themselves in a bubble.

“What does still nag at me was my failure to fully appreciate how susceptible we had become to lies and conspiracy theories, despite being a target of disinformation myself,” he said, referring to, among other things, the false debate over his U.S. birth certificate.

I think back to all the times I’ve heard Grandma nag at him about his blood pressure and not eating too much salt.