I kid, I kid.
One of the many valuable life lessons I learned at my mother's knee was to never let a book be inscribed. Don't inscribe a book to someone, and don't let an author inscribe a book to you. As a collector, Mom sees inscriptions as a desecration of a book.
I tend to agree to a certain extent. In my search for a signed first printing of Postmortem by Patricia Cornwell, I was constantly dismayed to find things like "To Gertrude" or "Dear Boris, enjoy the read" sullying the title pages of otherwise perfect copies. It was Mom who finally gifted me a pristine edition of Cornwell's first novel this past Christmas.
However, I do find something remarkably comforting about inscriptions from authors to me as well as inscriptions found in old books. My copy of The Curse-Maker by Kelli Stanley includes the inscription, "For Patrick--book lover, pen aficionado, and wonderful guy!!" To me, this is one of the most valuable books in my library.
Another favorite note is found inside my copy of A Girl Named Zippy by Haven Kimmel. It reads, "To Patrick, these weird little pictures of the past." Again, good ole Mom got this signed for me when I had the flu in 9th grade. Do we see a theme developing folks?
As I mentioned before, I love old books with inscriptions. They are brief glimpses into someone else's life. I have a dictionary given to a young girl by her aunt in 1936. I know this thanks to the note on the inside cover. Without it, it would be just another dictionary. Now it's something special. An old book about Elizabeth I was owned by a girl named Nancy M. Stevens in the 1950s, as noted on the front free end paper. Miss Stevens had good taste.
My favorite inscription without a doubt comes from an 1890 edition of Swiss Family Robinson. The flowery sepia colored cursive reads, "To Otto--With Love, Allie--March 26th, 1891." Who were Otto and Allie? Husband and wife? Boyfriend and girlfriend? How did this copy, inscribed almost 120 years ago, end up in a Friends of the Library Sale? The inscription is a story in itself. One where I get to write the plot.
In short, it's really up to you whether or not to have your book inscribed. Although it may lose its monetary value, the sentimental value never diminishes.
Oh, and I also wanted to mention that when I was cataloging Mom's Sue Grafton collection (go ahead and laugh) I found an INSCRIBED copy! The horror! The lies! Right there on the title page of 'B' Is for Burglar was the inscription, "To Mary, Yours till the end of crime, Sue Grafton." When I showed the book to Mom she admitted that it was pretty cool. I think so too.