it's a form of obsession, or obsessive thinking:
perseverance of thought. (That's per-SEV-er-ance, not
per-se-VER-ance)

Just listen again
The difference is plain:

When you do it again
And again and again
'Cause you don't want to stop
That's "perserverance".

When you think it again
And again and again
But you wish it would stop
That's "perseverance".