i needed an extraction done. i remember sitting down in the chair and telling the dentist "if you hurt me, i'm not coming back." he said, "No problem, i'm going to give you all the nitrous oxide you want. if i'm not giving you enough gas, just signal with your hand, and i'll give you more.
i inhaled as deeply as i good and held it as long as i could. then again. and again. when he asked me if i was feeling it yet, i told him no, even though i was in outer space. i kept inhaling and holding it, over and over. i could hear him talking with the nurse in the background. i just kept breathing in that gas.
after a while, the dentist started shaking me. I looked up and said, "what?"
he said, "hey, can't you hear me talking to you?"
i said, "i thought you were talking to somebody else."
he said, "there is nobody else here."
i said, "oh. well, what do you want?"
he said, "i wanted to know if you had enough gas. but i guess you have."
i really laughed about that later.