There is not much worse than getting off course during a race. In my half marathon PR race, I ended up running half of a mile in the wrong direction because the course marshal at that post stepped away. A bystander told me I was headed the wrong way and I ended up making it to the finish line for a PR.
Ever since then I have studied course maps for all of my races so I have a general understanding of where I should be headed. I highly suggest it for all runners for all races, no runner likes a surprise on race day. Plus, it’s always great to know where every aid station is because I am a drinker and can never be too hydrated when I’m running.