I've heard a few versions of that chestnut, but the only one which both rhymes and scans is this: 'Oh, what a tangled web we weave, when first we practice to deceive.'
...
"But when we've practiced quite a while
How vastly we improve our style!"
( - J. R. Pope, A Word of Encouragement. Collected in The New Oxford Book of English Light Verse, 1978.)
The important followup behaviour to this is whether people continue to deceive.