Charles Dudley Warner's notes from autobiography of Samuel Clemens concerning his education.
Charles Dudley Warner, “Clemen's 1873 Autobiographical Notes, and Biographical Sketch,” in Autobiography of Mark Twain, Volume 3: The Complete and Authoritative Edition, ed. Benjamin Griffin et al., by Mark Twain, 1st ed. (University of California Press, Oakland, California; London, England, 2015), 644
Attended the ordinary western common school in Hannibal, Mo., from the age of 5 till near the age of 13. That's all the education—if schooling—if playing hookey & getting licked for it may be called by that name.