Heard this one from my MSgt the other day and thought it was pretty good.
A man retires from the Marine Corps after 20 years of honorable service. He gets hired into a respectable job. His first day of work, he shows up an hour late. His boss notices, but says nothing about it, figuring something important must have kept him. The next day, he shows up 2 hours late. The boss again says nothing. This continues through the whole week, and on Friday, the boss finally decides he needs to say something. He pulls the retired Marine aside and says "You've been late every day this week. I know you're a retired Marine, and we'd expect your type to be early every day. What would they say to you in the Marine Corps if you showed up late every day like this?"
The retired Marine replies: "They'd say good morning, Top"