My HD
Let's see, nine years ago I fell down a flight of stairs, 1d6 damage, and dislocated my right elbow, which would have made me disabled. So I would say that I had 1 HD at the time.
Two years later I fell of my bike going through a Wal-Mart parking lot and dislocated my other elbow. Again disabled. So I still had 1 HD.
A week ago I was attacked by a dog and it bit me twice. A dog does 1d4+1 and I believe the first attack was a charge (luckily I had my jacket on so the bites only bruised me). So it did 2d4 + 5 damage (no criticals thank God) and was nowhere near a negative condition, so that was at least 8 to 14 hit points. So about 3 HD.
As for my class, its definitely expert. My skills are knowledge (gaming) since I am conversant with every edition of D&D (and almost every other TSR RPG), with Gurps, Hero, Traveller, Runequest, Swordbearer, Talislanta, Kult, and White Wolf games. Knowledge (earth and physical sciences, mostly physical sciences) with me about to get my second physics degree, Knowledge (life sciences) with me about to start my Planetary Science PhD with emphasis in Microbiology, Knowledge (philosophy and theology) as a personal hobby, Knowledge (history) again as a personal hobby, knowledge (humanities) from my years at a liberal arts college and I have a rank or two in Computer Use, and I am currently working on a rank in Repair. And I blew my feats on Educated and on skill focus (knowledge: gaming) and skill focus (knowledge: earth and physical sciences).