I know of one girl who is like that as well. She's a friend of mine who said she wanted to try and get stoned with me because she didn't get high her first couple of times. So, I got some dank, a pipe, her and her friend and we're at my house. It was her friends first time, and her third of fourth time.

We pack (I pack) and smoke a bowl and they both say they're not feeling anything. First off all, the girl is a complete idiot. She actually said, "How do I inhale?" I'm like, "......." So I had to teach her by taking hits and showing her how it's done. Well, she does what I do, uses the carb, then takes her finger off ETC ETC. She's barely getting a hit. Finally, she learns and gets 3 huge hits. Her friend is actually okay, she smokes cigarettes and does it that way and gets hits.
So, we end up packing 2 more bowls. Well, my friend didn't get high. At all. And I was like, "Dang sorry dude." But, it sorta pissed me off because she kept lighting the weed and I was like, "YOU'RE WASTING IT! THAT SHIT IS EXPENSIVE!" I didn't say that because she was new and all. So, I had some pills that I can't remember what they were. Well, she didn't get high, but she snorted the pills and she was frickin'.gone!

Anyway, she doesn't get high and her sister (a very good friend of mine, ^_^) gets blazed, but she ends up puking when she comes down. Apparently their mother said that when she was their age she tried smoking and couldn't get high either, so I'm thinking it runs in the genes.

On a side note, her friend was fucking retarded. She was trying to act stoned but you could tell she wasn't. That pissed me off too.
I was just in a bad mood, I guess. ^_^