My favorite professor (Wayne Phillips, RIP) was a WWII P-38 survivor of 5 parachute exits. Note - when exiting a P-38 cockpit in level flight, the pilot leaves the cockpit at a level significantly above the horizontal stabilizer, making one think seriously of the laws of physics that Gary has mentioned. Wayne said he perfected his exit procedure thus: after verifying it was time to leave the aircraft, 1) cinch the parachute straps, 2) get rid of the canopy, 3) crank the seat all the way up, 4) release the seat belt, and 5) roll the plane upside-down, push the stick forward, and fall out, well-clear of the meat-cleaver horizontal stabilizer.
He also claimed to have invented a drink that combined French Gin and powdered orange juice, called a "Phillips screw-driver". I miss him.