Both quotes are about the same piece of music – different people, though. Name the work referred to, and who said it.

“The cello is a beautiful instrument, but its place is in the orchestra and in chamber music. As a solo instrument it isn’t much good…I have….written a cello concerto, but am sorry to this day that I did so, and I never intend to write another”

And….

“Why on earth didn’t I know that one could write a cello concerto like this? If I had only known, I would have written one long ago!”

Thanks to the Lansdowne Symphony for writing the program notes that put these two quotes together.