I personally try to balance keeping myself honest by having some goal outside but also trusting myself enough to know when I should deprioritize the original goal in favor of something else.

For example, let's say I set a goal to write a blog post about a topic I'm learning in 4 hours, and half-way through I realize I don't understand one of the key underlying concepts related to the thing I intended to write about. During an actual test, the right thing to do would be to do my best given what I know already and finish as many questions as possible. But I'd argue that in the blog post case, I very well may be better off saying, "OK I'm going to go learn about this other thing until I understand it, even if I don't end up finishing the post I wanted to write."

The pithy way to say this is that tests are basically pure Goodhardt, and it's dangerous to turn every real life task into a game of maximizing legible metrics.