Probably because it was pretty clear he hadn't managed to convince himself yet.

Officials have even managed to convince many people that they are moving forward on environmental policy.

I don't know exactly what he said, but he'd managed to convince her.

After all, it has not yet managed to convince me.

He had put it all together in his mind and now he'd managed to convince himself.

But for a while, managed to convince themselves that they weren't significant.

He'd managed to convince himself of that, but only because he had wanted to believe it.

"On all of those issues, we have not managed to convince them."

There was much that he had managed to convince himself of.

He'd managed to convince himself everything was okay, but now he knew better.