I bought the beautiful second edition of Horn and Johnson’s Matrix Analysis at the SIAM meeting in Chicago last week. This morning I biked in to the office with the book in my bag, looking forward to adding it to my linear algebra collection.

But I had an uneasy feeling. Was it possible I had already bought this volume earlier, and forgotten? It was a relief to reach my office and find that no, it wasn’t already on the shelf. I didn’t own two copies.

Curious, eh? Given a choice between owning two copies of a fine book and just one, I preferred the latter.

[14 July 2014]