Sunday morning and it was the usual leftovers from the Saturday night. And of course the usual moans about hangovers and vows about "never drinking again." And even without gazing into a crystal ball I can reliably predict that they will do exactly the same next weekend. This constant repetition, when it's obvious that it going to end up in another painful hangover has always baffled me. This is even though I myself have admittedly done the same daft thing in the dim and distant past. But all was explained to me today when I picked up a fare who was a health professional specializing in drug and alcohol abuse. She explained that the brain has a built in defence mechanism which tells itself to forget about pain quickly. Go on test it yourself, try to remember exactly what your last toothache felt like. Yes you know it hurt, but your brain won't let you recreate that pain. But it still doesn't explain the guy who I picked up later on that same day. He staggered out of the pub as drunk as a lord and fell into the cab. "I haven't seen you for a while" I remarked "aye I just got out of rehab after six weeks" he slurred. Then as shook my head in puzzlement, he told me, as if it was quite normal that "he had been out for a good drink to celebrate!"