A philosopher named Harry G. Frankfurt wrote a brilliant essay a number of years ago entitled, "On BS". The title notwithstanding, the essay brilliantly examines a phenomenon you're going to see your whole life: people who say things for the effect of the saying, not the truth or falsehood of what it is they say.
I'm not going to try to restate Frankfurt's essay here. He does a fine job on his own. I want to focus on what this means to you.
Words are generally a means to an end. That end may be to convey information, rally support, provoke a fight, fulfill the requirements of an oral exam, or whatever. Those words you use will typically be one of three categories: words you believe to be true, words you believe to be false, and words you believe will have some sort of impact regardless of their truth or falsehood ("BS").
To be an effective storyteller, you must be an effective BSer. It's the nature of the business. People know that your words are not necessarily true; they realize those words are intended to create an effect and bizarrely they pay you to BS to them. Many other entertainers must be masters of BS in one form or another to do their jobs.
I believe that many of our biggest problems -- both personally and as a society -- arise when we persuade ourselves not that what is false is true, but that which is BS is true. The difference is subtle but important. Frankfurt has this to say about it:
Both in lying and in telling the truth people are guided by their beliefs concerning the way things are. These guide them as they endeavor either to describe the world correctly or to describe it deceitfully. For this reason, telling lies does not tend to unfit a person for telling the truth in the same way that [BS] tends to. ...The [BS]er ignores these demands altogether. He does not reject the authority of the truth, as the liar does, and oppose himself to it. He pays no attention to it at all. By virtue of this, [BS] is a greater enemy of the truth than lies are.
I'm not going to advise my older children to never lie. The truth is, lying is an important skill under varying circumstances: to protect others, to protect yourself, to make yourself look better, and to get out of trouble, among other reasons. It's extremely important to realize that everybody lies. Especially the people who tell you they never lie; that statement itself is guaranteed to be a lie. As long as you avoid being a pathological liar -- someone who lies frequently and for no good reason other than compulsion -- you're really no different than everybody else in that regard. It's important to know that your ability to discern a lie is really no better than random chance; in fact, you are more likely to believe a lie from a loved one than a stranger.
Those you believe to frequently tell the truth usually have some reasons they do so:
1. It's much easier to remember the truth than a lie. Telling the truth is pretty straightforward; you don't have to keep multiple stories straight or come up with weak excuses. This is the primary reason I advocate for telling the truth as a pragmatic measure.
2. They have some sort of personal religious, moral, or ethical bias toward truth-telling rather than falsehoods.
3. Gaining a reputation for telling the truth means that when one absolutely, positively needs to lie, that lie is much more likely to be believed.
I encourage my children for all of the reasons above to tell the truth as much as possible even when it is uncomfortable to do so. Telling the truth about yourself -- including your failings -- typically makes you look BETTER than you would otherwise, as it causes you to appear humble and self-effacing, even when an impressive lie would be more convenient or useful. Telling the truth rather than a lie to avoid trouble convinces others you are ethical and willing to face the consequences of your actions; the consequences of doing something wrong and telling the truth about it are also usually much lighter than the consequences of doing something wrong and lying about it. Sticking to the truth when describing events helps you remember and keep the story straight.
If you must lie, it's important to know the truth yourself, and the lie should be carefully planned and not spontaneous. Spontaneous lies are extremely easy to crack through. One just needs to look hard enough. A well-planned lie works on multiple levels to obscure the truth. Certain careers in Intelligence, for instance, require such lies to protect lives and prevent tragedy. These jobs are rare, but exist; you should consider carefully whether you're willing to live that way.
Above all, save the BS for entertaining people. Avoid using BS to try to get your way; that's the path frequently used by politicians, lawyers, and CEOs. It often works, but it takes a terrible personal and professional cost. There is a reason those in these kinds of positions are typically so widely reviled. I -- and H.G. Frankfurt -- call that reason BS.