When I was an ROTC cadet I got a back seat ride in an F-4. Got so sick I thought I was going to die. Practically had to be helped out of the cockpit. Made me real nervous about going to pilot training. Spent a few weeks of pilot training fighting passive airsickness, but managed to get over it without the chair. I think it was a combination of nerves and wearing all the gear that you're not used to...and that kerosene smell that the T-37 always had. I still remember how great if felt the first time I flew without feeling sick.