Oh what a tangled web

''Oh what a tangled web we weave when first we practice to deceive''
from Sir Walter Scott's long poem, Marmion

Deception is a false reality imposed on a true reality. It is a fragile and complex weaving of truth, half truths', lies and lies of omission. To successfully deceive another or several people, one must be skilled in the art of deception. To create a deception worthy of belief one must be able to create plausible details that help create the illusion of truth. It is the details that people listen to and remember and the one deceiving is obligated to remember these detail in order to avoid having the lie exposed. The problem with remembering the lies we tell is that all people are basically good and we tend to forget the bad things we've done. In order to successfully perpetuate deception, the liar must be willing to live that lie when necessary. This becomes the tangled web we weave, especially when first we practice to deceive.
It means if you tell lies you'd better have a really good memory or you'll end up in a tangle of lies, half-truths and truths.
Habitual liars can frequently be easily recognised because they like to keep various groups of friends and acquaintances separate for fear they'll exchange notes, thus causing the web to unravel.
It's amusing to watch a confirmed liar finding themself at a function where, say, workmates and friends are present together; they fidget and glance nervously at the various groups...who'd probably never wonder about their tales except for their nervous behavior.