And there's no such thing as a stupid question.
If you think that's bad, I didn't know that the flight levels skip 2,000 feet about FL300 until my second year at Delta!
like FL310, FL330, FL350, FL370
We were flying from SEA to CVG when I was a 727 flight engineer. We hit an area of nasty turbulence, but if we went lower, we'd increase our fuel burn, but an extra 1000' would get us over the clouds.
"Captain - we're too heavy to go to FL350, but we'd have the 'margin' to make FL340"
co-pilot: "Can't get to 340"
me: "Yeah, we could make 340, and 350 after another 20 minutes of fuel burn"
captain: *laughs*
me: "huh?"
captain: "Dumass, there's no such 'thang' as FL 340, only 310, 330, 350, 370, etc."
me: "no, really?"
doh!