This week I learned how to suffer a needle stick. I also learned how easily this can happen. Luckily, it was an unused, clean needle... this time. Moral of the story: if the cap sticks, get a new needle. There's little benefit in wrestling with an object designed to puncture skin.
Additionally, expect the unexpected. Just because you never covered a topic in any of your classes (auer rods) doesn't mean you won't get a histology slide on exam testing if you can visually recognize it and diagnose based on it's presence.