The motivation for misusing or overusing 'Literally' seems to be either the desire to sound more intelligent than the speaker actually is, or to make the statement more profound to the hearer's ear.

A good test to find out if you are overusing 'Literally' is to write your sentence down and look at it. Remove the word 'Literally'. Does the remaining sentence retain the exact same meaning, without that word? If so, then you are overusing 'Literally'.

Compounding the issue is the misuse of the word, often at the same time as the overuse of it. The misuse comes when a speaker doesn't realize that 'Literally' means "adhering to the meaning of the words". I recently told a person about a great new restaurant, and he replied that "I literally just rolled by that place this afternoon." Mental images of this person lying down on the pavement and rolling past the restaurant sailed through my mind. It would have been pointless to mention that misuse, since he would immediately become defensive and not even try to comprehend what is being said.

In my opinion, the overuse & misuse of the word 'Literally' is so common that intelligent people should stop using it entirely. It is a rare thing to hear "Literally" being used correctly.