Liars have a very good memory
Good liars have an excellent memory, and they can remember the most absurd details in order to keep themselves from contradicting their previous actions and lies.
Liars withhold their information
The less they speak, the fewer lies they are forced to remember, right? Even if good liars can easily remember all the needed details, they still know that the best thing to do is to avoid getting tangled up in their own lies.
Liars will “forget” some stuff on purpose, especially when it comes up to fabricated stories. It’s their own way of manipulating you. However, you need to remember: not telling the entire truth is still seen as lying.