Playing Beethoven again

Some months ago a friend gave me the three volumes of Beethoven piano sonatas in hardcover. They'd never been used, and though they were fairly elderly, they were in pristine condition.

I hadn't played the sonatas for some time, although I've had the books since I was a teenager, and learned them most of them (with a few exceptions) as a young man. During the years I've come back to them a number of times, but had found myself less and less enamoured of them for some reason.

Over the summer hol...