Mark Twain: Instructive

Portrait of Samuel Clemens as a youth holding ...

Portrait of Samuel Clemens as a youth holding a printer’s composing stick with letters SAM. Daguerreotype; sixth plate. Plate mark: Scovill. Inscribed in case well: G.H.[?] Jones Jonco? / Hannibal Mo / 1850 / Nov. 29th. On case pad: Samuel L. Clem-/ens – [illegible] / Taken Dec. 1850 / Age 15. (Photo credit: Wikipedia)

“I cannot keep from talking, even at the risk of being instructive.”
Mark Twain.