Excerpt from Letting Go by Philip Roth

"The X-rays, a check-up," he said vaguely.  "Hygiene aside, consider it a matter of curiosity.  A matter of self-investigation.  Know thyself, you know?  I'm acquainted with people who think of dentists as mechanics, carpenters, nobodies.  Ridiculous.  Dentists are astronomers -- just let me go on -- dentists are geologists.  Gabe, when seen from the proper angle, dentistry is a romance.  Take the stars.  I see the fellow next door up on the roof charting stars.  'Charting' them, is that right?  Looking, examining, and so forth.  Now I want to put it this way: what's so different about dentistry?  I'm serious now -- what's so different about getting directly at what's in a man's head?  Not millions of light years away, but right here -- God Almightly, almost touching the brain.  Now there are cases, documented cases of the tooth actually piercing the brain.  Can you imagine?  So galaxies, solar systems -- believe me, a tooth is just as much a mystery as a star.  A man's got to have a philosophy of life, why he works, and that's mine.  You get older and you wonder why you do what you do.  A man doesn't get along without reasons.  To go through life, just putting on your garters and eating your food, alone, by myself, without sufficient reasons, day after day, how can a fellow do it?  Unless he's got like Gruber, smiling sickness, smiling on the brain.  For myself, Gabe, I need a little mystery in life.  As I get older I haven't got a lot of the old concerns, you know.  Well, I find much to think about in terms of the human mouth.  The third molar alone could occupy a lifetime.  Don't laugh -- that's a fact.  Just the why of it, I'm telling you...Life makes you stop and think, that's the thing.  Life changes on a man, and then he's got to have a little something in reserve.  I feel a little ashamed about what I didn't have in reserve."  He had then to go look off for a moment in another direction.  "Look, I don't have to go on and on.  It's nice to talk to someone who understands.  Lean back again, I want to clean them."