He's probably not a pig shit farmer...not everyone can be selected to guard the tomb...You don't just walk back and forth clicking your heels...it's the pinnacle of a rigorous selection process.. http://www.tombguard.org/general.html
Being selected to stand watch over the graves of the Unknown Soldiers is one of the highest honors a soldier in the United States Army can be granted. Selection is very rigorous.
First and foremost, you must be an enlisted member of the United States Army, between the ranks of Private (E-1) through Sergeant First Class (E-7). The Tomb Guards are selected from only one unit in the Army, the 3d U.S. Infantry (The Old Guard) which is stationed at Fort Myer, Virginia.
However, getting to the Old Guard is tough, as you must pass the standards set for the entire Regiment. Once in the Old Guard you must serve for at least 6 months, before submitting your name to the Tomb.
Just some of the requirements that each candidate must have:
No military or civilian convictions of law
Score a minimum of 250 on the Army Physical Fitness Test
Be with in 5'11" - 6'4"
Have a 30 inch waist
Present a soldierly appearance in the Army Blue Uniform.
If you serve 9 months, you get to keep the silver badge and ribbon on your uniform. The tests are hardcore, you have to memorize 7 pages of rules and facts, plus learn over 300 graves locations. Pass an oral examine that requires a 95% to pass and then MAYBE you will get to assist in the daily changing of the guard. No diet privates, midgets or shade tree soldiers need apply.
i've personally witnessed someone acting like a asshole at the ceremony. The staff sgt. performing the ceremony came within 5 feet of the asshole and berated him much worse than this soldier did. When you act inappropriately in a place like this, you deserve nothing less.