The worst time I ever passed out was when I tried contacts. (I had a vasovagal reaction - I've had them before, but not so intense.) I actually had a little dream while I passed out and, like you, had to remember where I was and why I was there. I, too, visited a friend in the hospital once and had to go out into the hall and find a chair to sit in. I have read that drinking more water and consuming more salt when you suspect you are entering a situation that will cause a reaction can help, especially if they are truly vasovagal reactions. Good luck. I don't even bother donating blood. About 90% of my post-18-year-old life I've been unable to anyway due to body modifications like tattoos and piercings. Currently I won't be eligible til Sept 5, 2015. They kicked my dad out of the blood bank because he passed out every time so I suspect I have a genetic influence to my reactions too. They also seem to come on when I have low blood sugar.