Ross think of it like this. Are any of those other "Good'ol Farm Boys" any more likely to have applied themselves in school than you? I know some real meatheads on fire departments, if they can make it through the schooling so can you.
Also, you were smart enough to get Lisa to marry you, you ain't no dummy.
And just so you head doesn't get too big, if they want you on the department they won't let the schooling that holds you back. They give you any help you need to get through and pass. It is in their best interest for you to learn and pass and join the team.