I'm preeeeetty sure this happened to me once. I was like 18 and I thought I was just being a whiny little cunt (even though I never said anything about it), so I never spoke up. Then, the next time I went, I didn't feel a thing, and my cheek was all numb afterwards and all that standard stuff, and I was like, "Oh yeah, this is what it's like; I guess I wasn't just being a wimp before."