You need to be honest to yourself and to those in your orbit. A lot of people enjoy a tall tail or exaggeration when they’re looking to be entertained. But when those small exaggerations bleed into real life serious situations, it is not good.
As someone who employs people, I need to give honest assessments so each person on my team knows where they stand and where they can improve or how they can grow to do more. If I lie to someone, I’m giving them false hope and that is not fair.
As an employee if you are asked to fulfill a set of responsibilities, those tasks are given to you because your boss trusts that you can do it. If for some reason you can’t accomplish all the tasks, it is better to let your manager know so the team can figure a solution to help you. If you aren’t truthful and are struggling to do the required tasks, a client can get a half baked widget, or your team under performs for the big presentation, or you just feel so overwhelmed you quit.
Being open and honest with your actions and communication is of the upmost importance. When you need to say no someone, instead of using the classic “But…” and interject some sort of white lie just say the truth. Just say “No. Maybe next time.” That’s it.