Mark Twain, an avid cigar smoker, tried to quit or cut back on several occasions. "To cease smoking is the easiest thing," he once declared. "I ought to know -- I've done it a thousand times!"
["Never put off until tomorrow," Twain once advised, "what you can do the day after tomorrow."]
[In Following the Equator he wrote, "I pledged myself to smoke but one cigar a day. I kept the cigar waiting until bedtime, then I had a luxurious time with it. But desire persecuted me every day and all day long. I found myself hunting for larger cigars... within the month my cigar had grown to such proportions that I could have used it as a crutch."]
Sources
Mark Twain, Following the Equator; Justin Kaplan, Mr. Clemens & Mark Twain: A Biography