It might seem like a bunch of bs but there are some real idiots that go to these classes. I went to school for cars and i had a guy grease the brakes on time, another was using a air drill and set it down between his legs while it was still chugging it grabbed is pants by the ankle and well he almost lost his buddies we pulled airline just before it happened. Also had a guy dropp the jack quickly while removing coil springs it shot out and went into the brick wall. See my point its for you're safety as much as their dumba$$.