Another offbeat thing to do in London is to check out the British Science Museum's exhibits on the history of medicine. It certainly gives you an appreciation for modern technology - for better or worse.
In the display you'll find old medical instruments that you would think had been used to torture prisoners, not to heal patients. Pacemakers were the size of a 4x4, a roof-shaft made for a blood-cooling device, kidney dialysis was performed with what looked like something out of a Dr. Seuss book.
There is also a section with sculptures depicting the historical evolution of medicine. It really shows how far we've come in the last 2000 years. In the earliest days, the museum shows how the cavemen believed that sickness was caused by demons in the brain, so they'd use rocks to make holes in peoples' skulls to let the demons escape. On the Roman battlefield, soldiers would be healed in private homes. During the Medieval times, cathedrals served as hospitals. During battles at sea in the 17th to 19th centuries, some people got limbs amputated without anything but a shot of whisky and a piece of leather to bite on for comfort.
Even on land, people were not drugged before surgical operations up through the mid-1800s. The surgeon would perform operations in a suit and bare hands and other people could stand around and observe. Until the early 20th century, doctors' offices were normally just a furnished room in their house (sometimes this is still around today, but is rare).
After looking at how much things have evolved even in the last 50 years, I would rather wait another 50 years and let things evolve even more before my next doctor's appointment!