Sometimes what people identify in the NT world as 'the truth' is merely an opinion in which they're highly invested. Also, a belief in & a support of convention can masquerade as truth. Social truisms such as girls are this way & boys are that way (the substance of this & that vary from culture to culture) are merely expectations & stereotypes in disguise. Is a person, for instance, who has changed their hair colour radically (like from brown to blonde) popped in tinted contacts, gotten a spray tan & a bunch of other alterations a liar? Are they wearing a disguise? Trying to appear as something other than what they are?
Sometimes, the difference between the truth & a lie lies in the intention of the 'liar'. If you ask me if I like your new hair do & I say, "No. I think you look like a bantam rooster." Am I being honest & truthful or am I merely expressing my opinion in a malicious manner? Did the person really want to hear my 'honest' opinion or were they seeking some kind of validation & a confidence boost because they were perhaps not sure about their new look? If I say, "YES! I love it!" when I really don't am I truly a liar or practicing NT world social diplomacy?
Truth is seldom absolute. I recall the case of a woman who was raped in her home in broad daylight. She was face to face with her attacker & strove to memorize his face. She identified him in a police line-up & was certain she was identifying the right man. She WAS telling the truth as she understood it & her only intention was to obtain justice. The guy did 14 years when DNA evidence freed him. By coincidence, the real rapist was sitting in the same prison on an unrelated crime. The 2 men did share an uncanny resemblance. This woman was devastated & felt terrible guilt. In an odd twist, she became friendly with the wrongfully convicted man & he forgave her.
I like to gauge my intentions before having to lie about something. Like the rest of you, I can do it BUT I hate to & always feel cornered into it. Last week, my mother was going to visit my father in the hospital. She asked me how she looked before leaving the house. I replied a neutral, non-committal 'fine'. IMO, which was what she was asking for, she looked awful but what would my truthful opinion have caused?
Unless there is a clear-cut line between the truth & a lie, it is a giant grey area. If you stole the neighbour's car & when the cops asked you, you said, "No: it wasn't me." then you are a liar. If you are delusional or a confused person, you might even believe that you didn't really steal it but that the neighbour owed it to you for some reason.
A lot of the time on news shows & political debates, a politician will say something like, "the truth is....." or "the reality is...." which implies that any other opinion & perspective is inherently false. This is a strategy to elevate of the status their own personal opinion to the level of an empirical truth.