A few weeks before boarding a ship in Argentina to cross the notorious Drake Passage on the way to Antarctica, I asked my doctor for a couple of scopolamine patches in case the going got rough.  Scopolamine is the drug of choice for those of us who are prone to seasickness; worn behind the ear, it's more effective than over-the-counter anti-nausea drugs, and once it's on, you pretty much forget about it.  The problem is that you pretty much forget about everything else, too.  I had no idea.  I put on the patch and went about my business.  The boat crossed a calm Drake, we made it to the Antarctic Peninsula in record time, and before long I was standing on Penguin Island looking at...penguins.  Good thing I was taking notes and taking pictures, because the next day, while I recalled stepping off on to the island, and the multitude of wildlife there, it was a fuzzy memory at best, like a picture that's almost in focus.  What I didn't know--what, in fact, pretty much none of the other passengers didn't know--was that scopolamine interferes with memory.  This is because it's an anticholinergic agent, and blocks the neurotransmitter acetylcholine.  By way of contrast, the Alzheimer's drug Aricept is designed to increase acetylcholine, which is in short supply in Alzheimer's patients.  Boosting acetylcholine is thought to boost memory.